Issue summary: A signed integer overflow when sizing the destination buffer for Unicode output in ASN1_mbstring_ncopy() can lead to a heap buffer overflow. Impact summary: A heap buffer overflow may lead to a crash or possibly attacker controlled code execution or other undefined behaviour. In ASN1_mbstring_copy() and ASN1_mbstring_ncopy() the destination size for Unicode output is computed in a signed int: by left shift of the input character count for BMPSTRING (UTF-16) and UNIVERSALSTRING (UTF-32), and by summing per-character byte counts for UTF8STRING. The calculation overflows when the input reaches around 2^30 characters. In the worst case (UNIVERSALSTRING at 2^30 characters) the size wraps to zero, OPENSSL_malloc(1) is called, and the subsequent character copy writes several gigabytes past the one-byte allocation. X.509 certificate processing routes through ASN1_STRING_set_by_NID(), whose DIRSTRING_TYPE mask excludes UNIVERSALSTRING and whose per-NID size limits cap the input length; no network protocol or certificate-handling path in OpenSSL exercises the overflow. Triggering the bug requires an application that calls ASN1_mbstring_copy() or ASN1_mbstring_ncopy() directly, or registers a custom string type via ASN1_STRING_TABLE_add(), with attacker-controlled input on the order of half a gigabyte or more. For these reasons this issue was assigned Low severity. The FIPS modules in 4.0, 3.6, 3.5, 3.4 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.

freebsd a57fe2c1-6476-11f1-958d-bc241121aa0a: FreeBSD -- Multiple vulnerabilities in OpenSSL

The remote Ubuntu 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8414-1 advisory.

    Frank Buss discovered that OpenSSL had a heap buffer over-read in ASN.1 content parsing. An attacker could     possibly use this issue to cause OpenSSL to crash, resulting in a denial of service, or obtain sensitive     information. (CVE-2026-34180)

    Pavol Zacik and Alex Gaynor discovered that OpenSSL incorrectly accepted PKCS#12 files with short HMAC     keys when using PBMAC1. An attacker could possibly use this issue to bypass integrity checks. This issue     only affected Ubuntu 25.10 and Ubuntu 26.04 LTS. (CVE-2026-34181)

    Asim Viladi Oglu Manizada and Alex Gaynor discovered that OpenSSL could accept forged CMS     AuthEnvelopedData messages. An attacker could possibly use this issue to bypass message authentication     checks. (CVE-2026-34182)

    Abhinav Agarwal discovered that OpenSSL had unbounded memory growth in the QUIC PATH_CHALLENGE handler. A     remote attacker could possibly use this issue to cause OpenSSL to use excessive resources, leading to a     denial of service. This issue only affected Ubuntu 25.10 and Ubuntu 26.04 LTS. (CVE-2026-34183)

    Sunwoo Lee, Hyuk Lim, and Seunghyun Yoon discovered that OpenSSL had a NULL pointer dereference in QUIC     server initial packet handling. A remote attacker could possibly use this issue to cause OpenSSL to crash,     resulting in a denial of service. This issue only affected Ubuntu 25.10 and Ubuntu 26.04 LTS.
    (CVE-2026-42764)

    Mayank Jangid, Kushal Khemka, Hari Priandana, Bhabani Sankar Das, and Qifan Zhang discovered that OpenSSL     had a possible NULL dereference in password- based CMS decryption. An attacker could possibly use this     issue to cause OpenSSL to crash, resulting in a denial of service. (CVE-2026-42766)

    Zhanpeng Liu, Guannan Wang, and Guancheng Li discovered that OpenSSL had a NULL pointer dereference in     CRMF EncryptedValue decryption. An attacker could possibly use this issue to cause OpenSSL to crash,     resulting in a denial of service. (CVE-2026-42767)

    Alex Gaynor discovered that OpenSSL had a Bleichenbacher oracle in CMS_decrypt() and PKCS7_decrypt() with     multiple RecipientInfo values. An attacker could possibly use this issue to obtain sensitive information.
    This issue only affected Ubuntu 25.10 and Ubuntu 26.04 LTS. (CVE-2026-42768)

    Alex Gaynor discovered that OpenSSL had a trust-anchor substitution issue in CMP rootCaKeyUpdate     processing. An attacker could possibly use this issue to bypass certificate trust validation. This issue     only affected Ubuntu 25.10 and Ubuntu 26.04 LTS. (CVE-2026-42769)

    Alex Gaynor discovered that OpenSSL used attacker-supplied parameters when validating FFC-DH peers. An     attacker could possibly use this issue to weaken key validation and compromise security guarantees.
    (CVE-2026-42770)

    Alex Gaynor discovered that OpenSSL could ignore the IV in AES-OCB mode on the EVP_Cipher() path. An     attacker could possibly use this issue to bypass cryptographic protections and obtain sensitive     information. (CVE-2026-45445)

    Alex Gaynor discovered that OpenSSL had incorrect tag processing for empty messages in AES-GCM-SIV and     AES-SIV modes. An attacker could possibly use this issue to bypass cryptographic integrity checks.
    (CVE-2026-45446)

    Thai Duong discovered that OpenSSL had a heap use-after-free in PKCS7_verify(). An attacker could possibly     use this issue to cause OpenSSL to crash, resulting in a denial of service, or execute arbitrary code.
    (CVE-2026-45447)

    Zehua Qiao and Jinwen He discovered that OpenSSL had a possible heap buffer overflow in ASN.1 multibyte     string conversion. An attacker could possibly use this issue to cause OpenSSL to crash, resulting in a     denial of service, or execute arbitrary code. (CVE-2026-7383)

    Bhabani Sankar Das discovered that OpenSSL had an out-of-bounds read in CMS password-based decryption. An     attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service.
    (CVE-2026-9076)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Issue summary: A signed integer overflow when sizing the destination buffer for Unicode output in     ASN1_mbstring_ncopy() can lead to a heap buffer overflow. Impact summary: A heap buffer overflow may lead     to a crash or possibly attacker controlled code execution or other undefined behaviour. In     ASN1_mbstring_copy() and ASN1_mbstring_ncopy() the destination size for Unicode output is computed in a     signed int: by left shift of the input character count for BMPSTRING (UTF-16) and UNIVERSALSTRING     (UTF-32), and by summing per-character byte counts for UTF8STRING. The calculation overflows when the     input reaches around 2^30 characters. In the worst case (UNIVERSALSTRING at 2^30 characters) the size     wraps to zero, OPENSSL_malloc(1) is called, and the subsequent character copy writes several gigabytes     past the one-byte allocation. X.509 certificate processing routes through ASN1_STRING_set_by_NID(), whose     DIRSTRING_TYPE mask excludes UNIVERSALSTRING and whose per-NID size limits cap the input length; no     network protocol or certificate-handling path in OpenSSL exercises the overflow. Triggering the bug     requires an application that calls ASN1_mbstring_copy() or ASN1_mbstring_ncopy() directly, or registers a     custom string type via ASN1_STRING_TABLE_add(), with attacker-controlled input on the order of half a     gigabyte or more. For these reasons this issue was assigned Low severity. The FIPS modules in 4.0, 3.6,     3.5, 3.4 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module     boundary. (CVE-2026-7383)

Note that Nessus relies on the presence of the package as reported by the vendor.

The remote Debian 12 / 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6335 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6335-1                   security@debian.org     https://www.debian.org/security/                     Salvatore Bonaccorso     June 09, 2026                         https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : openssl     CVE ID         : CVE-2026-7383 CVE-2026-9076 CVE-2026-34180 CVE-2026-34181                      CVE-2026-34182 CVE-2026-34183 CVE-2026-42764 CVE-2026-42766                      CVE-2026-42767 CVE-2026-42768 CVE-2026-42769 CVE-2026-42770                      CVE-2026-45445 CVE-2026-45446 CVE-2026-45447

    Multiple vulnerabilities have been discovered in OpenSSL, a Secure     Sockets Layer toolkit, which may result in denial of service,     information leaks, or potentially remote code execution.

    Additional details can be found in the upstream advisory:
    https://openssl-library.org/news/secadv/20260609.txt

    For the oldstable distribution (bookworm), these problems have been fixed     in version 3.0.20-1~deb12u2.

    For the stable distribution (trixie), these problems have been fixed in     version 3.5.6-1~deb13u2.

    We recommend that you upgrade your openssl packages.

    For the detailed security status of openssl please refer to its security     tracker page at:
    https://security-tracker.debian.org/tracker/openssl

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of OpenSSL installed on the remote host is prior to 3.0.21. It is, therefore, affected by multiple vulnerabilities as referenced in the 3.0.21 advisory.

  - Issue summary: A specially crafted PKCS#7 or S/MIME signed message could trigger a use-after-free during     PKCS#7 signature verification. Impact summary: A use-after-free may result in process crashes, heap     corruption, or potentially remote code execution. When processing a PKCS#7 or S/MIME signed message, if     the SignedData digestAlgorithms field is present as an empty ASN.1 SET, OpenSSL may incorrectly free a     caller-owned BIO during PKCS7_verify(). A subsequent use of the BIO by the calling application results in     a use-after-free condition. In the common case this occurs when the application later calls BIO_free() on     the BIO originally passed to PKCS7_verify(). Depending on allocator behavior and application-specific BIO     usage patterns, this may result in a crash or other memory corruption. In some application contexts this     may potentially be exploitable for remote code execution. Applications that process PKCS#7 or S/MIME     signed messages using OpenSSL PKCS#7 APIs may be affected. Applications using the CMS APIs for this     processing are not affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this     issue, as the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-45447)

  - Issue summary: When CMS password-based decryption (RFC 3211 / PWRI key unwrap) processes attacker-supplied     CMS data, an attacker-chosen stream-mode KEK cipher can trigger a heap out-of-bounds read in     kek_unwrap_key(). Impact summary: A heap buffer over-read may trigger a crash which leads to Denial of     Service for an application if the input buffer ends at a memory page boundary and the following page is     unmapped. There is no information disclosure as the over-read bytes are not revealed to the attacker. The     key unwrapping function performs a check-byte test as specified in the RFC that reads 7 bytes from a heap     allocation that is based on the wrapped key length from the message. There is a minimum length check based     on the block length of the wrapping cipher. However the cipher is selected from an OID carried in the     attacker's PWRI keyEncryptionAlgorithm with no requirement that the cipher be a block cipher. When an     attacker selects a stream-mode cipher the guard will be ineffective and the allocated buffer containing     the unwrapped key can be too small to fit the check-bytes specified in the RFC and a buffer over-read can     happen. Applications calling CMS_decrypt() or CMS_decrypt_set1_password() (equivalently openssl cms
    -decrypt -pwri_password ...) on untrusted CMS data are vulnerable to this issue. No password knowledge is     required: the over-read happens during the unwrap attempt before any authentication succeeds. The over-     read is limited to a few bytes and is not written to output, so there is no information disclosure.
    Triggering a crash requires the allocation to border unmapped memory, which is unlikely with the normal     allocator. The FIPS modules are not affected by this issue. (CVE-2026-9076)

  - Issue summary: A signed integer overflow when sizing the destination buffer for Unicode output in     ASN1_mbstring_ncopy() can lead to a heap buffer overflow. Impact summary: A heap buffer overflow may lead     to a crash or possibly attacker controlled code execution or other undefined behaviour. In     ASN1_mbstring_copy() and ASN1_mbstring_ncopy() the destination size for Unicode output is computed in a     signed int: by left shift of the input character count for BMPSTRING (UTF-16) and UNIVERSALSTRING     (UTF-32), and by summing per-character byte counts for UTF8STRING. The calculation overflows when the     input reaches around 2^30 characters. In the worst case (UNIVERSALSTRING at 2^30 characters) the size     wraps to zero, OPENSSL_malloc(1) is called, and the subsequent character copy writes several gigabytes     past the one-byte allocation. X.509 certificate processing routes through ASN1_STRING_set_by_NID(), whose     DIRSTRING_TYPE mask excludes UNIVERSALSTRING and whose per-NID size limits cap the input length; no     network protocol or certificate-handling path in OpenSSL exercises the overflow. Triggering the bug     requires an application that calls ASN1_mbstring_copy() or ASN1_mbstring_ncopy() directly, or registers a     custom string type via ASN1_STRING_TABLE_add(), with attacker-controlled input on the order of half a     gigabyte or more. For these reasons this issue was assigned Low severity. The FIPS modules in 4.0, 3.6,     3.5, 3.4 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module     boundary. (CVE-2026-7383)

  - Issue summary: The implementations of AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) mishandle the     authentication of AAD (Additional Authenticated Data) with an empty ciphertext allowing a forgery of such     messages. Impact summary: An attacker can forge empty messages with arbitrary AAD to the victim's     application using these ciphers. AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) are nonce-misuse-resistant     AEAD modes: they accept a key, nonce, optional AAD (bytes that are authenticated but not encrypted), and     plaintext, and produces ciphertext plus a 16-byte tag. On decrypt, `EVP_DecryptFinal_ex()` is documented     to return success only if the tag is verified succesfully. In OpenSSL's provider implementation of these     ciphers, the expected tag is computed only when decryption function is invoked with non-empty data. If the     caller supplies AAD and then calls `EVP_DecryptFinal_ex()` without invocation of the ciphertext update,     which can happen when the received ciphertext length is zero, the tag is never recalculated and still     holds its all-zeros value. When AES-GCM-SIV is used, an attacker who sends arbitrary AAD, empty     ciphertext, and all-zeros tag passes authentication under any key they do not know, single-shot. When AES-     SIV is used, for mounting the attack it's necessary for the application to reuse the decryption context     without resetting the key. AES-SIV is implemented since OpenSSL 3.0. AES-GCM-SIV is implemented since     OpenSSL 3.2. No protocols implemented in OpenSSL itself (TLS/CMS/PKCS7/HPKE/QUIC) support either AES-GCM-     SIV or AES-SIV. To mount an attack, the applications must implement their own protocol and use the EVP     interface. Also they must skip the ciphertext update when a message with an empty ciphertext arrives. The     FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as these algorithms are not     FIPS approved and the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-45446)

  - Issue summary: When an application drives an AES-OCB context through the public EVP_Cipher() one-shot     interface, the application-supplied initialisation vector (IV) is silently discarded. Impact summary:
    Every message encrypted under the same key uses the same effective nonce regardless of the IV supplied by     the caller, resulting in (key, nonce) reuse and loss of confidentiality. If the same code path is used to     compute the authentication tag, the tag depends only on the (key, IV) pair and not on the plaintext or     ciphertext, allowing universal forgery of arbitrary ciphertext from a single captured message. OpenSSL     provides two ways to drive a cipher: the documented streaming interface (EVP_CipherUpdate /     EVP_CipherFinal_ex) and a lower-level one-shot, EVP_Cipher(), whose documentation explicitly recommends     against use by applications in favour of EVP_CipherUpdate() and EVP_CipherFinal_ex(). The OCB provider's     streaming handler flushes the application-supplied IV into the OCB context before processing data; the     one-shot handler did not. Every call to EVP_Cipher() on an AES-OCB context therefore ran with the all-zero     key-derived offset state left by cipher initialisation, regardless of the caller's IV. If     EVP_EncryptFinal_ex() is subsequently used to obtain the authentication tag, the deferred IV setup runs at     that point and clears the running checksum that should have been accumulated over the plaintext. The     resulting tag is a function of (key, IV) only and verifies against any ciphertext produced under the same     (key, IV) pair. The OpenSSL SSL/TLS implementation is not affected: AES-OCB is not a TLS cipher suite, and     libssl does not call EVP_Cipher() in any case. Applications that drive AES-OCB through the documented     streaming AEAD API (EVP_CipherUpdate / EVP_CipherFinal_ex) are not affected. Only applications that     combine the AES-OCB cipher with the EVP_Cipher() one-shot API are vulnerable. The FIPS modules in 4.0,     3.6, 3.5, 3.4 and 3.0 are not affected by this issue, as AES-OCB is outside the OpenSSL FIPS module     boundary. (CVE-2026-45445)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of OpenSSL installed on the remote host is prior to 1.0.2zq. It is, therefore, affected by multiple vulnerabilities as referenced in the 1.0.2zq advisory.

  - Issue summary: A specially crafted password-encrypted CMS message can trigger a NULL pointer dereference     during CMS decryption. Impact summary: This NULL pointer dereference leads to an application crash and a     Denial of Service. The CMS PasswordRecipientInfo.keyDerivationAlgorithm field is defined as OPTIONAL in     the ASN.1 specification and may therefore be absent in specially crafted inputs. During the password-based     CMS decryption the OpenSSL CMS implementation dereferences this field without first checking whether it     was present. An attacker who supplies such a CMS message to an application performing password-based CMS     decryption can trigger an application crash, leading to a Denial of Service. Applications that process     password-encrypted CMS messages may be affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not     affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-42766)

  - Issue summary: A signed integer overflow when sizing the destination buffer for Unicode output in     ASN1_mbstring_ncopy() can lead to a heap buffer overflow. Impact summary: A heap buffer overflow may lead     to a crash or possibly attacker controlled code execution or other undefined behaviour. In     ASN1_mbstring_copy() and ASN1_mbstring_ncopy() the destination size for Unicode output is computed in a     signed int: by left shift of the input character count for BMPSTRING (UTF-16) and UNIVERSALSTRING     (UTF-32), and by summing per-character byte counts for UTF8STRING. The calculation overflows when the     input reaches around 2^30 characters. In the worst case (UNIVERSALSTRING at 2^30 characters) the size     wraps to zero, OPENSSL_malloc(1) is called, and the subsequent character copy writes several gigabytes     past the one-byte allocation. X.509 certificate processing routes through ASN1_STRING_set_by_NID(), whose     DIRSTRING_TYPE mask excludes UNIVERSALSTRING and whose per-NID size limits cap the input length; no     network protocol or certificate-handling path in OpenSSL exercises the overflow. Triggering the bug     requires an application that calls ASN1_mbstring_copy() or ASN1_mbstring_ncopy() directly, or registers a     custom string type via ASN1_STRING_TABLE_add(), with attacker-controlled input on the order of half a     gigabyte or more. For these reasons this issue was assigned Low severity. The FIPS modules in 4.0, 3.6,     3.5, 3.4 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module     boundary. (CVE-2026-7383)

  - Issue summary: When CMS password-based decryption (RFC 3211 / PWRI key unwrap) processes attacker-supplied     CMS data, an attacker-chosen stream-mode KEK cipher can trigger a heap out-of-bounds read in     kek_unwrap_key(). Impact summary: A heap buffer over-read may trigger a crash which leads to Denial of     Service for an application if the input buffer ends at a memory page boundary and the following page is     unmapped. There is no information disclosure as the over-read bytes are not revealed to the attacker. The     key unwrapping function performs a check-byte test as specified in the RFC that reads 7 bytes from a heap     allocation that is based on the wrapped key length from the message. There is a minimum length check based     on the block length of the wrapping cipher. However the cipher is selected from an OID carried in the     attacker's PWRI keyEncryptionAlgorithm with no requirement that the cipher be a block cipher. When an     attacker selects a stream-mode cipher the guard will be ineffective and the allocated buffer containing     the unwrapped key can be too small to fit the check-bytes specified in the RFC and a buffer over-read can     happen. Applications calling CMS_decrypt() or CMS_decrypt_set1_password() (equivalently openssl cms
    -decrypt -pwri_password ...) on untrusted CMS data are vulnerable to this issue. No password knowledge is     required: the over-read happens during the unwrap attempt before any authentication succeeds. The over-     read is limited to a few bytes and is not written to output, so there is no information disclosure.
    Triggering a crash requires the allocation to border unmapped memory, which is unlikely with the normal     allocator. The FIPS modules are not affected by this issue. (CVE-2026-9076)

  - Issue summary: A specially crafted PKCS#7 or S/MIME signed message could trigger a use-after-free during     PKCS#7 signature verification. Impact summary: A use-after-free may result in process crashes, heap     corruption, or potentially remote code execution. When processing a PKCS#7 or S/MIME signed message, if     the SignedData digestAlgorithms field is present as an empty ASN.1 SET, OpenSSL may incorrectly free a     caller-owned BIO during PKCS7_verify(). A subsequent use of the BIO by the calling application results in     a use-after-free condition. In the common case this occurs when the application later calls BIO_free() on     the BIO originally passed to PKCS7_verify(). Depending on allocator behavior and application-specific BIO     usage patterns, this may result in a crash or other memory corruption. In some application contexts this     may potentially be exploitable for remote code execution. Applications that process PKCS#7 or S/MIME     signed messages using OpenSSL PKCS#7 APIs may be affected. Applications using the CMS APIs for this     processing are not affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this     issue, as the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-45447)

  - Issue summary: Parsing a crafted DER-encoded ASN.1 structure with a primitive element whose content     exceeds 2 gigabytes in length may cause a heap buffer over-read on 64-bit Unix and Unix-like platforms.
    Impact summary: The heap buffer over-read may crash the application (Denial of Service) or to load into     the decoded ASN.1 object contents of memory beyond the end of the input buffer. More typically such ASN.1     elements would instead be truncated. An integer truncation in OpenSSL's ASN.1 decoder causes the content     length of an ASN.1 primitive element to be mishandled when it exceeds 2 gigabytes. In the worst case the     truncated length is treated as a request to scan the binary content for a terminating zero byte, possibly     causing OpenSSL to read either less than or beyond the end of the allocated buffer. Applications that pass     attacker-supplied data to d2i_X509(), d2i_PKCS7(), or any other d2i_* decoding function are affected.
    OpenSSL's own command-line tools are not vulnerable, as data read through the BIO layer is checked before     it reaches the affected code. The issue only affects 64-bit Unix and Unix-like platforms; 32-bit platforms     and 64-bit Windows are not affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4 and 3.0 are not affected by     this issue, as the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-34180)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of OpenSSL installed on the remote host is prior to 4.0.1. It is, therefore, affected by multiple vulnerabilities as referenced in the 4.0.1 advisory.

  - Issue summary: A specially crafted PKCS#7 or S/MIME signed message could trigger a use-after-free during     PKCS#7 signature verification. Impact summary: A use-after-free may result in process crashes, heap     corruption, or potentially remote code execution. When processing a PKCS#7 or S/MIME signed message, if     the SignedData digestAlgorithms field is present as an empty ASN.1 SET, OpenSSL may incorrectly free a     caller-owned BIO during PKCS7_verify(). A subsequent use of the BIO by the calling application results in     a use-after-free condition. In the common case this occurs when the application later calls BIO_free() on     the BIO originally passed to PKCS7_verify(). Depending on allocator behavior and application-specific BIO     usage patterns, this may result in a crash or other memory corruption. In some application contexts this     may potentially be exploitable for remote code execution. Applications that process PKCS#7 or S/MIME     signed messages using OpenSSL PKCS#7 APIs may be affected. Applications using the CMS APIs for this     processing are not affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this     issue, as the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-45447)

  - Issue summary: When CMS password-based decryption (RFC 3211 / PWRI key unwrap) processes attacker-supplied     CMS data, an attacker-chosen stream-mode KEK cipher can trigger a heap out-of-bounds read in     kek_unwrap_key(). Impact summary: A heap buffer over-read may trigger a crash which leads to Denial of     Service for an application if the input buffer ends at a memory page boundary and the following page is     unmapped. There is no information disclosure as the over-read bytes are not revealed to the attacker. The     key unwrapping function performs a check-byte test as specified in the RFC that reads 7 bytes from a heap     allocation that is based on the wrapped key length from the message. There is a minimum length check based     on the block length of the wrapping cipher. However the cipher is selected from an OID carried in the     attacker's PWRI keyEncryptionAlgorithm with no requirement that the cipher be a block cipher. When an     attacker selects a stream-mode cipher the guard will be ineffective and the allocated buffer containing     the unwrapped key can be too small to fit the check-bytes specified in the RFC and a buffer over-read can     happen. Applications calling CMS_decrypt() or CMS_decrypt_set1_password() (equivalently openssl cms
    -decrypt -pwri_password ...) on untrusted CMS data are vulnerable to this issue. No password knowledge is     required: the over-read happens during the unwrap attempt before any authentication succeeds. The over-     read is limited to a few bytes and is not written to output, so there is no information disclosure.
    Triggering a crash requires the allocation to border unmapped memory, which is unlikely with the normal     allocator. The FIPS modules are not affected by this issue. (CVE-2026-9076)

  - Issue summary: A signed integer overflow when sizing the destination buffer for Unicode output in     ASN1_mbstring_ncopy() can lead to a heap buffer overflow. Impact summary: A heap buffer overflow may lead     to a crash or possibly attacker controlled code execution or other undefined behaviour. In     ASN1_mbstring_copy() and ASN1_mbstring_ncopy() the destination size for Unicode output is computed in a     signed int: by left shift of the input character count for BMPSTRING (UTF-16) and UNIVERSALSTRING     (UTF-32), and by summing per-character byte counts for UTF8STRING. The calculation overflows when the     input reaches around 2^30 characters. In the worst case (UNIVERSALSTRING at 2^30 characters) the size     wraps to zero, OPENSSL_malloc(1) is called, and the subsequent character copy writes several gigabytes     past the one-byte allocation. X.509 certificate processing routes through ASN1_STRING_set_by_NID(), whose     DIRSTRING_TYPE mask excludes UNIVERSALSTRING and whose per-NID size limits cap the input length; no     network protocol or certificate-handling path in OpenSSL exercises the overflow. Triggering the bug     requires an application that calls ASN1_mbstring_copy() or ASN1_mbstring_ncopy() directly, or registers a     custom string type via ASN1_STRING_TABLE_add(), with attacker-controlled input on the order of half a     gigabyte or more. For these reasons this issue was assigned Low severity. The FIPS modules in 4.0, 3.6,     3.5, 3.4 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module     boundary. (CVE-2026-7383)

  - Issue summary: The implementations of AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) mishandle the     authentication of AAD (Additional Authenticated Data) with an empty ciphertext allowing a forgery of such     messages. Impact summary: An attacker can forge empty messages with arbitrary AAD to the victim's     application using these ciphers. AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) are nonce-misuse-resistant     AEAD modes: they accept a key, nonce, optional AAD (bytes that are authenticated but not encrypted), and     plaintext, and produces ciphertext plus a 16-byte tag. On decrypt, `EVP_DecryptFinal_ex()` is documented     to return success only if the tag is verified succesfully. In OpenSSL's provider implementation of these     ciphers, the expected tag is computed only when decryption function is invoked with non-empty data. If the     caller supplies AAD and then calls `EVP_DecryptFinal_ex()` without invocation of the ciphertext update,     which can happen when the received ciphertext length is zero, the tag is never recalculated and still     holds its all-zeros value. When AES-GCM-SIV is used, an attacker who sends arbitrary AAD, empty     ciphertext, and all-zeros tag passes authentication under any key they do not know, single-shot. When AES-     SIV is used, for mounting the attack it's necessary for the application to reuse the decryption context     without resetting the key. AES-SIV is implemented since OpenSSL 3.0. AES-GCM-SIV is implemented since     OpenSSL 3.2. No protocols implemented in OpenSSL itself (TLS/CMS/PKCS7/HPKE/QUIC) support either AES-GCM-     SIV or AES-SIV. To mount an attack, the applications must implement their own protocol and use the EVP     interface. Also they must skip the ciphertext update when a message with an empty ciphertext arrives. The     FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as these algorithms are not     FIPS approved and the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-45446)

  - Issue summary: When an application drives an AES-OCB context through the public EVP_Cipher() one-shot     interface, the application-supplied initialisation vector (IV) is silently discarded. Impact summary:
    Every message encrypted under the same key uses the same effective nonce regardless of the IV supplied by     the caller, resulting in (key, nonce) reuse and loss of confidentiality. If the same code path is used to     compute the authentication tag, the tag depends only on the (key, IV) pair and not on the plaintext or     ciphertext, allowing universal forgery of arbitrary ciphertext from a single captured message. OpenSSL     provides two ways to drive a cipher: the documented streaming interface (EVP_CipherUpdate /     EVP_CipherFinal_ex) and a lower-level one-shot, EVP_Cipher(), whose documentation explicitly recommends     against use by applications in favour of EVP_CipherUpdate() and EVP_CipherFinal_ex(). The OCB provider's     streaming handler flushes the application-supplied IV into the OCB context before processing data; the     one-shot handler did not. Every call to EVP_Cipher() on an AES-OCB context therefore ran with the all-zero     key-derived offset state left by cipher initialisation, regardless of the caller's IV. If     EVP_EncryptFinal_ex() is subsequently used to obtain the authentication tag, the deferred IV setup runs at     that point and clears the running checksum that should have been accumulated over the plaintext. The     resulting tag is a function of (key, IV) only and verifies against any ciphertext produced under the same     (key, IV) pair. The OpenSSL SSL/TLS implementation is not affected: AES-OCB is not a TLS cipher suite, and     libssl does not call EVP_Cipher() in any case. Applications that drive AES-OCB through the documented     streaming AEAD API (EVP_CipherUpdate / EVP_CipherFinal_ex) are not affected. Only applications that     combine the AES-OCB cipher with the EVP_Cipher() one-shot API are vulnerable. The FIPS modules in 4.0,     3.6, 3.5, 3.4 and 3.0 are not affected by this issue, as AES-OCB is outside the OpenSSL FIPS module     boundary. (CVE-2026-45445)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of OpenSSL installed on the remote host is prior to 1.1.1zh. It is, therefore, affected by multiple vulnerabilities as referenced in the 1.1.1zh advisory.

  - Issue summary: A specially crafted password-encrypted CMS message can trigger a NULL pointer dereference     during CMS decryption. Impact summary: This NULL pointer dereference leads to an application crash and a     Denial of Service. The CMS PasswordRecipientInfo.keyDerivationAlgorithm field is defined as OPTIONAL in     the ASN.1 specification and may therefore be absent in specially crafted inputs. During the password-based     CMS decryption the OpenSSL CMS implementation dereferences this field without first checking whether it     was present. An attacker who supplies such a CMS message to an application performing password-based CMS     decryption can trigger an application crash, leading to a Denial of Service. Applications that process     password-encrypted CMS messages may be affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not     affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-42766)

  - Issue summary: A signed integer overflow when sizing the destination buffer for Unicode output in     ASN1_mbstring_ncopy() can lead to a heap buffer overflow. Impact summary: A heap buffer overflow may lead     to a crash or possibly attacker controlled code execution or other undefined behaviour. In     ASN1_mbstring_copy() and ASN1_mbstring_ncopy() the destination size for Unicode output is computed in a     signed int: by left shift of the input character count for BMPSTRING (UTF-16) and UNIVERSALSTRING     (UTF-32), and by summing per-character byte counts for UTF8STRING. The calculation overflows when the     input reaches around 2^30 characters. In the worst case (UNIVERSALSTRING at 2^30 characters) the size     wraps to zero, OPENSSL_malloc(1) is called, and the subsequent character copy writes several gigabytes     past the one-byte allocation. X.509 certificate processing routes through ASN1_STRING_set_by_NID(), whose     DIRSTRING_TYPE mask excludes UNIVERSALSTRING and whose per-NID size limits cap the input length; no     network protocol or certificate-handling path in OpenSSL exercises the overflow. Triggering the bug     requires an application that calls ASN1_mbstring_copy() or ASN1_mbstring_ncopy() directly, or registers a     custom string type via ASN1_STRING_TABLE_add(), with attacker-controlled input on the order of half a     gigabyte or more. For these reasons this issue was assigned Low severity. The FIPS modules in 4.0, 3.6,     3.5, 3.4 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module     boundary. (CVE-2026-7383)

  - Issue summary: When CMS password-based decryption (RFC 3211 / PWRI key unwrap) processes attacker-supplied     CMS data, an attacker-chosen stream-mode KEK cipher can trigger a heap out-of-bounds read in     kek_unwrap_key(). Impact summary: A heap buffer over-read may trigger a crash which leads to Denial of     Service for an application if the input buffer ends at a memory page boundary and the following page is     unmapped. There is no information disclosure as the over-read bytes are not revealed to the attacker. The     key unwrapping function performs a check-byte test as specified in the RFC that reads 7 bytes from a heap     allocation that is based on the wrapped key length from the message. There is a minimum length check based     on the block length of the wrapping cipher. However the cipher is selected from an OID carried in the     attacker's PWRI keyEncryptionAlgorithm with no requirement that the cipher be a block cipher. When an     attacker selects a stream-mode cipher the guard will be ineffective and the allocated buffer containing     the unwrapped key can be too small to fit the check-bytes specified in the RFC and a buffer over-read can     happen. Applications calling CMS_decrypt() or CMS_decrypt_set1_password() (equivalently openssl cms
    -decrypt -pwri_password ...) on untrusted CMS data are vulnerable to this issue. No password knowledge is     required: the over-read happens during the unwrap attempt before any authentication succeeds. The over-     read is limited to a few bytes and is not written to output, so there is no information disclosure.
    Triggering a crash requires the allocation to border unmapped memory, which is unlikely with the normal     allocator. The FIPS modules are not affected by this issue. (CVE-2026-9076)

  - Issue summary: A specially crafted PKCS#7 or S/MIME signed message could trigger a use-after-free during     PKCS#7 signature verification. Impact summary: A use-after-free may result in process crashes, heap     corruption, or potentially remote code execution. When processing a PKCS#7 or S/MIME signed message, if     the SignedData digestAlgorithms field is present as an empty ASN.1 SET, OpenSSL may incorrectly free a     caller-owned BIO during PKCS7_verify(). A subsequent use of the BIO by the calling application results in     a use-after-free condition. In the common case this occurs when the application later calls BIO_free() on     the BIO originally passed to PKCS7_verify(). Depending on allocator behavior and application-specific BIO     usage patterns, this may result in a crash or other memory corruption. In some application contexts this     may potentially be exploitable for remote code execution. Applications that process PKCS#7 or S/MIME     signed messages using OpenSSL PKCS#7 APIs may be affected. Applications using the CMS APIs for this     processing are not affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this     issue, as the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-45447)

  - Issue summary: Parsing a crafted DER-encoded ASN.1 structure with a primitive element whose content     exceeds 2 gigabytes in length may cause a heap buffer over-read on 64-bit Unix and Unix-like platforms.
    Impact summary: The heap buffer over-read may crash the application (Denial of Service) or to load into     the decoded ASN.1 object contents of memory beyond the end of the input buffer. More typically such ASN.1     elements would instead be truncated. An integer truncation in OpenSSL's ASN.1 decoder causes the content     length of an ASN.1 primitive element to be mishandled when it exceeds 2 gigabytes. In the worst case the     truncated length is treated as a request to scan the binary content for a terminating zero byte, possibly     causing OpenSSL to read either less than or beyond the end of the allocated buffer. Applications that pass     attacker-supplied data to d2i_X509(), d2i_PKCS7(), or any other d2i_* decoding function are affected.
    OpenSSL's own command-line tools are not vulnerable, as data read through the BIO layer is checked before     it reaches the affected code. The issue only affects 64-bit Unix and Unix-like platforms; 32-bit platforms     and 64-bit Windows are not affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4 and 3.0 are not affected by     this issue, as the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-34180)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of OpenSSL installed on the remote host is prior to 3.4.6. It is, therefore, affected by multiple vulnerabilities as referenced in the 3.4.6 advisory.

  - Issue summary: A specially crafted PKCS#7 or S/MIME signed message could trigger a use-after-free during     PKCS#7 signature verification. Impact summary: A use-after-free may result in process crashes, heap     corruption, or potentially remote code execution. When processing a PKCS#7 or S/MIME signed message, if     the SignedData digestAlgorithms field is present as an empty ASN.1 SET, OpenSSL may incorrectly free a     caller-owned BIO during PKCS7_verify(). A subsequent use of the BIO by the calling application results in     a use-after-free condition. In the common case this occurs when the application later calls BIO_free() on     the BIO originally passed to PKCS7_verify(). Depending on allocator behavior and application-specific BIO     usage patterns, this may result in a crash or other memory corruption. In some application contexts this     may potentially be exploitable for remote code execution. Applications that process PKCS#7 or S/MIME     signed messages using OpenSSL PKCS#7 APIs may be affected. Applications using the CMS APIs for this     processing are not affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this     issue, as the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-45447)

  - Issue summary: When CMS password-based decryption (RFC 3211 / PWRI key unwrap) processes attacker-supplied     CMS data, an attacker-chosen stream-mode KEK cipher can trigger a heap out-of-bounds read in     kek_unwrap_key(). Impact summary: A heap buffer over-read may trigger a crash which leads to Denial of     Service for an application if the input buffer ends at a memory page boundary and the following page is     unmapped. There is no information disclosure as the over-read bytes are not revealed to the attacker. The     key unwrapping function performs a check-byte test as specified in the RFC that reads 7 bytes from a heap     allocation that is based on the wrapped key length from the message. There is a minimum length check based     on the block length of the wrapping cipher. However the cipher is selected from an OID carried in the     attacker's PWRI keyEncryptionAlgorithm with no requirement that the cipher be a block cipher. When an     attacker selects a stream-mode cipher the guard will be ineffective and the allocated buffer containing     the unwrapped key can be too small to fit the check-bytes specified in the RFC and a buffer over-read can     happen. Applications calling CMS_decrypt() or CMS_decrypt_set1_password() (equivalently openssl cms
    -decrypt -pwri_password ...) on untrusted CMS data are vulnerable to this issue. No password knowledge is     required: the over-read happens during the unwrap attempt before any authentication succeeds. The over-     read is limited to a few bytes and is not written to output, so there is no information disclosure.
    Triggering a crash requires the allocation to border unmapped memory, which is unlikely with the normal     allocator. The FIPS modules are not affected by this issue. (CVE-2026-9076)

  - Issue summary: A signed integer overflow when sizing the destination buffer for Unicode output in     ASN1_mbstring_ncopy() can lead to a heap buffer overflow. Impact summary: A heap buffer overflow may lead     to a crash or possibly attacker controlled code execution or other undefined behaviour. In     ASN1_mbstring_copy() and ASN1_mbstring_ncopy() the destination size for Unicode output is computed in a     signed int: by left shift of the input character count for BMPSTRING (UTF-16) and UNIVERSALSTRING     (UTF-32), and by summing per-character byte counts for UTF8STRING. The calculation overflows when the     input reaches around 2^30 characters. In the worst case (UNIVERSALSTRING at 2^30 characters) the size     wraps to zero, OPENSSL_malloc(1) is called, and the subsequent character copy writes several gigabytes     past the one-byte allocation. X.509 certificate processing routes through ASN1_STRING_set_by_NID(), whose     DIRSTRING_TYPE mask excludes UNIVERSALSTRING and whose per-NID size limits cap the input length; no     network protocol or certificate-handling path in OpenSSL exercises the overflow. Triggering the bug     requires an application that calls ASN1_mbstring_copy() or ASN1_mbstring_ncopy() directly, or registers a     custom string type via ASN1_STRING_TABLE_add(), with attacker-controlled input on the order of half a     gigabyte or more. For these reasons this issue was assigned Low severity. The FIPS modules in 4.0, 3.6,     3.5, 3.4 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module     boundary. (CVE-2026-7383)

  - Issue summary: The implementations of AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) mishandle the     authentication of AAD (Additional Authenticated Data) with an empty ciphertext allowing a forgery of such     messages. Impact summary: An attacker can forge empty messages with arbitrary AAD to the victim's     application using these ciphers. AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) are nonce-misuse-resistant     AEAD modes: they accept a key, nonce, optional AAD (bytes that are authenticated but not encrypted), and     plaintext, and produces ciphertext plus a 16-byte tag. On decrypt, `EVP_DecryptFinal_ex()` is documented     to return success only if the tag is verified succesfully. In OpenSSL's provider implementation of these     ciphers, the expected tag is computed only when decryption function is invoked with non-empty data. If the     caller supplies AAD and then calls `EVP_DecryptFinal_ex()` without invocation of the ciphertext update,     which can happen when the received ciphertext length is zero, the tag is never recalculated and still     holds its all-zeros value. When AES-GCM-SIV is used, an attacker who sends arbitrary AAD, empty     ciphertext, and all-zeros tag passes authentication under any key they do not know, single-shot. When AES-     SIV is used, for mounting the attack it's necessary for the application to reuse the decryption context     without resetting the key. AES-SIV is implemented since OpenSSL 3.0. AES-GCM-SIV is implemented since     OpenSSL 3.2. No protocols implemented in OpenSSL itself (TLS/CMS/PKCS7/HPKE/QUIC) support either AES-GCM-     SIV or AES-SIV. To mount an attack, the applications must implement their own protocol and use the EVP     interface. Also they must skip the ciphertext update when a message with an empty ciphertext arrives. The     FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as these algorithms are not     FIPS approved and the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-45446)

  - Issue summary: When an application drives an AES-OCB context through the public EVP_Cipher() one-shot     interface, the application-supplied initialisation vector (IV) is silently discarded. Impact summary:
    Every message encrypted under the same key uses the same effective nonce regardless of the IV supplied by     the caller, resulting in (key, nonce) reuse and loss of confidentiality. If the same code path is used to     compute the authentication tag, the tag depends only on the (key, IV) pair and not on the plaintext or     ciphertext, allowing universal forgery of arbitrary ciphertext from a single captured message. OpenSSL     provides two ways to drive a cipher: the documented streaming interface (EVP_CipherUpdate /     EVP_CipherFinal_ex) and a lower-level one-shot, EVP_Cipher(), whose documentation explicitly recommends     against use by applications in favour of EVP_CipherUpdate() and EVP_CipherFinal_ex(). The OCB provider's     streaming handler flushes the application-supplied IV into the OCB context before processing data; the     one-shot handler did not. Every call to EVP_Cipher() on an AES-OCB context therefore ran with the all-zero     key-derived offset state left by cipher initialisation, regardless of the caller's IV. If     EVP_EncryptFinal_ex() is subsequently used to obtain the authentication tag, the deferred IV setup runs at     that point and clears the running checksum that should have been accumulated over the plaintext. The     resulting tag is a function of (key, IV) only and verifies against any ciphertext produced under the same     (key, IV) pair. The OpenSSL SSL/TLS implementation is not affected: AES-OCB is not a TLS cipher suite, and     libssl does not call EVP_Cipher() in any case. Applications that drive AES-OCB through the documented     streaming AEAD API (EVP_CipherUpdate / EVP_CipherFinal_ex) are not affected. Only applications that     combine the AES-OCB cipher with the EVP_Cipher() one-shot API are vulnerable. The FIPS modules in 4.0,     3.6, 3.5, 3.4 and 3.0 are not affected by this issue, as AES-OCB is outside the OpenSSL FIPS module     boundary. (CVE-2026-45445)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of OpenSSL installed on the remote host is prior to 3.5.7. It is, therefore, affected by multiple vulnerabilities as referenced in the 3.5.7 advisory.

  - Issue summary: A specially crafted PKCS#7 or S/MIME signed message could trigger a use-after-free during     PKCS#7 signature verification. Impact summary: A use-after-free may result in process crashes, heap     corruption, or potentially remote code execution. When processing a PKCS#7 or S/MIME signed message, if     the SignedData digestAlgorithms field is present as an empty ASN.1 SET, OpenSSL may incorrectly free a     caller-owned BIO during PKCS7_verify(). A subsequent use of the BIO by the calling application results in     a use-after-free condition. In the common case this occurs when the application later calls BIO_free() on     the BIO originally passed to PKCS7_verify(). Depending on allocator behavior and application-specific BIO     usage patterns, this may result in a crash or other memory corruption. In some application contexts this     may potentially be exploitable for remote code execution. Applications that process PKCS#7 or S/MIME     signed messages using OpenSSL PKCS#7 APIs may be affected. Applications using the CMS APIs for this     processing are not affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this     issue, as the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-45447)

  - Issue summary: When CMS password-based decryption (RFC 3211 / PWRI key unwrap) processes attacker-supplied     CMS data, an attacker-chosen stream-mode KEK cipher can trigger a heap out-of-bounds read in     kek_unwrap_key(). Impact summary: A heap buffer over-read may trigger a crash which leads to Denial of     Service for an application if the input buffer ends at a memory page boundary and the following page is     unmapped. There is no information disclosure as the over-read bytes are not revealed to the attacker. The     key unwrapping function performs a check-byte test as specified in the RFC that reads 7 bytes from a heap     allocation that is based on the wrapped key length from the message. There is a minimum length check based     on the block length of the wrapping cipher. However the cipher is selected from an OID carried in the     attacker's PWRI keyEncryptionAlgorithm with no requirement that the cipher be a block cipher. When an     attacker selects a stream-mode cipher the guard will be ineffective and the allocated buffer containing     the unwrapped key can be too small to fit the check-bytes specified in the RFC and a buffer over-read can     happen. Applications calling CMS_decrypt() or CMS_decrypt_set1_password() (equivalently openssl cms
    -decrypt -pwri_password ...) on untrusted CMS data are vulnerable to this issue. No password knowledge is     required: the over-read happens during the unwrap attempt before any authentication succeeds. The over-     read is limited to a few bytes and is not written to output, so there is no information disclosure.
    Triggering a crash requires the allocation to border unmapped memory, which is unlikely with the normal     allocator. The FIPS modules are not affected by this issue. (CVE-2026-9076)

  - Issue summary: A signed integer overflow when sizing the destination buffer for Unicode output in     ASN1_mbstring_ncopy() can lead to a heap buffer overflow. Impact summary: A heap buffer overflow may lead     to a crash or possibly attacker controlled code execution or other undefined behaviour. In     ASN1_mbstring_copy() and ASN1_mbstring_ncopy() the destination size for Unicode output is computed in a     signed int: by left shift of the input character count for BMPSTRING (UTF-16) and UNIVERSALSTRING     (UTF-32), and by summing per-character byte counts for UTF8STRING. The calculation overflows when the     input reaches around 2^30 characters. In the worst case (UNIVERSALSTRING at 2^30 characters) the size     wraps to zero, OPENSSL_malloc(1) is called, and the subsequent character copy writes several gigabytes     past the one-byte allocation. X.509 certificate processing routes through ASN1_STRING_set_by_NID(), whose     DIRSTRING_TYPE mask excludes UNIVERSALSTRING and whose per-NID size limits cap the input length; no     network protocol or certificate-handling path in OpenSSL exercises the overflow. Triggering the bug     requires an application that calls ASN1_mbstring_copy() or ASN1_mbstring_ncopy() directly, or registers a     custom string type via ASN1_STRING_TABLE_add(), with attacker-controlled input on the order of half a     gigabyte or more. For these reasons this issue was assigned Low severity. The FIPS modules in 4.0, 3.6,     3.5, 3.4 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module     boundary. (CVE-2026-7383)

  - Issue summary: The implementations of AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) mishandle the     authentication of AAD (Additional Authenticated Data) with an empty ciphertext allowing a forgery of such     messages. Impact summary: An attacker can forge empty messages with arbitrary AAD to the victim's     application using these ciphers. AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) are nonce-misuse-resistant     AEAD modes: they accept a key, nonce, optional AAD (bytes that are authenticated but not encrypted), and     plaintext, and produces ciphertext plus a 16-byte tag. On decrypt, `EVP_DecryptFinal_ex()` is documented     to return success only if the tag is verified succesfully. In OpenSSL's provider implementation of these     ciphers, the expected tag is computed only when decryption function is invoked with non-empty data. If the     caller supplies AAD and then calls `EVP_DecryptFinal_ex()` without invocation of the ciphertext update,     which can happen when the received ciphertext length is zero, the tag is never recalculated and still     holds its all-zeros value. When AES-GCM-SIV is used, an attacker who sends arbitrary AAD, empty     ciphertext, and all-zeros tag passes authentication under any key they do not know, single-shot. When AES-     SIV is used, for mounting the attack it's necessary for the application to reuse the decryption context     without resetting the key. AES-SIV is implemented since OpenSSL 3.0. AES-GCM-SIV is implemented since     OpenSSL 3.2. No protocols implemented in OpenSSL itself (TLS/CMS/PKCS7/HPKE/QUIC) support either AES-GCM-     SIV or AES-SIV. To mount an attack, the applications must implement their own protocol and use the EVP     interface. Also they must skip the ciphertext update when a message with an empty ciphertext arrives. The     FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as these algorithms are not     FIPS approved and the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-45446)

  - Issue summary: When an application drives an AES-OCB context through the public EVP_Cipher() one-shot     interface, the application-supplied initialisation vector (IV) is silently discarded. Impact summary:
    Every message encrypted under the same key uses the same effective nonce regardless of the IV supplied by     the caller, resulting in (key, nonce) reuse and loss of confidentiality. If the same code path is used to     compute the authentication tag, the tag depends only on the (key, IV) pair and not on the plaintext or     ciphertext, allowing universal forgery of arbitrary ciphertext from a single captured message. OpenSSL     provides two ways to drive a cipher: the documented streaming interface (EVP_CipherUpdate /     EVP_CipherFinal_ex) and a lower-level one-shot, EVP_Cipher(), whose documentation explicitly recommends     against use by applications in favour of EVP_CipherUpdate() and EVP_CipherFinal_ex(). The OCB provider's     streaming handler flushes the application-supplied IV into the OCB context before processing data; the     one-shot handler did not. Every call to EVP_Cipher() on an AES-OCB context therefore ran with the all-zero     key-derived offset state left by cipher initialisation, regardless of the caller's IV. If     EVP_EncryptFinal_ex() is subsequently used to obtain the authentication tag, the deferred IV setup runs at     that point and clears the running checksum that should have been accumulated over the plaintext. The     resulting tag is a function of (key, IV) only and verifies against any ciphertext produced under the same     (key, IV) pair. The OpenSSL SSL/TLS implementation is not affected: AES-OCB is not a TLS cipher suite, and     libssl does not call EVP_Cipher() in any case. Applications that drive AES-OCB through the documented     streaming AEAD API (EVP_CipherUpdate / EVP_CipherFinal_ex) are not affected. Only applications that     combine the AES-OCB cipher with the EVP_Cipher() one-shot API are vulnerable. The FIPS modules in 4.0,     3.6, 3.5, 3.4 and 3.0 are not affected by this issue, as AES-OCB is outside the OpenSSL FIPS module     boundary. (CVE-2026-45445)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of OpenSSL installed on the remote host is prior to 3.6.3. It is, therefore, affected by multiple vulnerabilities as referenced in the 3.6.3 advisory.

  - Issue summary: A specially crafted PKCS#7 or S/MIME signed message could trigger a use-after-free during     PKCS#7 signature verification. Impact summary: A use-after-free may result in process crashes, heap     corruption, or potentially remote code execution. When processing a PKCS#7 or S/MIME signed message, if     the SignedData digestAlgorithms field is present as an empty ASN.1 SET, OpenSSL may incorrectly free a     caller-owned BIO during PKCS7_verify(). A subsequent use of the BIO by the calling application results in     a use-after-free condition. In the common case this occurs when the application later calls BIO_free() on     the BIO originally passed to PKCS7_verify(). Depending on allocator behavior and application-specific BIO     usage patterns, this may result in a crash or other memory corruption. In some application contexts this     may potentially be exploitable for remote code execution. Applications that process PKCS#7 or S/MIME     signed messages using OpenSSL PKCS#7 APIs may be affected. Applications using the CMS APIs for this     processing are not affected. The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this     issue, as the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-45447)

  - Issue summary: When CMS password-based decryption (RFC 3211 / PWRI key unwrap) processes attacker-supplied     CMS data, an attacker-chosen stream-mode KEK cipher can trigger a heap out-of-bounds read in     kek_unwrap_key(). Impact summary: A heap buffer over-read may trigger a crash which leads to Denial of     Service for an application if the input buffer ends at a memory page boundary and the following page is     unmapped. There is no information disclosure as the over-read bytes are not revealed to the attacker. The     key unwrapping function performs a check-byte test as specified in the RFC that reads 7 bytes from a heap     allocation that is based on the wrapped key length from the message. There is a minimum length check based     on the block length of the wrapping cipher. However the cipher is selected from an OID carried in the     attacker's PWRI keyEncryptionAlgorithm with no requirement that the cipher be a block cipher. When an     attacker selects a stream-mode cipher the guard will be ineffective and the allocated buffer containing     the unwrapped key can be too small to fit the check-bytes specified in the RFC and a buffer over-read can     happen. Applications calling CMS_decrypt() or CMS_decrypt_set1_password() (equivalently openssl cms
    -decrypt -pwri_password ...) on untrusted CMS data are vulnerable to this issue. No password knowledge is     required: the over-read happens during the unwrap attempt before any authentication succeeds. The over-     read is limited to a few bytes and is not written to output, so there is no information disclosure.
    Triggering a crash requires the allocation to border unmapped memory, which is unlikely with the normal     allocator. The FIPS modules are not affected by this issue. (CVE-2026-9076)

  - Issue summary: A signed integer overflow when sizing the destination buffer for Unicode output in     ASN1_mbstring_ncopy() can lead to a heap buffer overflow. Impact summary: A heap buffer overflow may lead     to a crash or possibly attacker controlled code execution or other undefined behaviour. In     ASN1_mbstring_copy() and ASN1_mbstring_ncopy() the destination size for Unicode output is computed in a     signed int: by left shift of the input character count for BMPSTRING (UTF-16) and UNIVERSALSTRING     (UTF-32), and by summing per-character byte counts for UTF8STRING. The calculation overflows when the     input reaches around 2^30 characters. In the worst case (UNIVERSALSTRING at 2^30 characters) the size     wraps to zero, OPENSSL_malloc(1) is called, and the subsequent character copy writes several gigabytes     past the one-byte allocation. X.509 certificate processing routes through ASN1_STRING_set_by_NID(), whose     DIRSTRING_TYPE mask excludes UNIVERSALSTRING and whose per-NID size limits cap the input length; no     network protocol or certificate-handling path in OpenSSL exercises the overflow. Triggering the bug     requires an application that calls ASN1_mbstring_copy() or ASN1_mbstring_ncopy() directly, or registers a     custom string type via ASN1_STRING_TABLE_add(), with attacker-controlled input on the order of half a     gigabyte or more. For these reasons this issue was assigned Low severity. The FIPS modules in 4.0, 3.6,     3.5, 3.4 and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module     boundary. (CVE-2026-7383)

  - Issue summary: The implementations of AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) mishandle the     authentication of AAD (Additional Authenticated Data) with an empty ciphertext allowing a forgery of such     messages. Impact summary: An attacker can forge empty messages with arbitrary AAD to the victim's     application using these ciphers. AES-SIV (RFC 5297) and AES-GCM-SIV (RFC 8452) are nonce-misuse-resistant     AEAD modes: they accept a key, nonce, optional AAD (bytes that are authenticated but not encrypted), and     plaintext, and produces ciphertext plus a 16-byte tag. On decrypt, `EVP_DecryptFinal_ex()` is documented     to return success only if the tag is verified succesfully. In OpenSSL's provider implementation of these     ciphers, the expected tag is computed only when decryption function is invoked with non-empty data. If the     caller supplies AAD and then calls `EVP_DecryptFinal_ex()` without invocation of the ciphertext update,     which can happen when the received ciphertext length is zero, the tag is never recalculated and still     holds its all-zeros value. When AES-GCM-SIV is used, an attacker who sends arbitrary AAD, empty     ciphertext, and all-zeros tag passes authentication under any key they do not know, single-shot. When AES-     SIV is used, for mounting the attack it's necessary for the application to reuse the decryption context     without resetting the key. AES-SIV is implemented since OpenSSL 3.0. AES-GCM-SIV is implemented since     OpenSSL 3.2. No protocols implemented in OpenSSL itself (TLS/CMS/PKCS7/HPKE/QUIC) support either AES-GCM-     SIV or AES-SIV. To mount an attack, the applications must implement their own protocol and use the EVP     interface. Also they must skip the ciphertext update when a message with an empty ciphertext arrives. The     FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as these algorithms are not     FIPS approved and the affected code is outside the OpenSSL FIPS module boundary. (CVE-2026-45446)

  - Issue summary: When an application drives an AES-OCB context through the public EVP_Cipher() one-shot     interface, the application-supplied initialisation vector (IV) is silently discarded. Impact summary:
    Every message encrypted under the same key uses the same effective nonce regardless of the IV supplied by     the caller, resulting in (key, nonce) reuse and loss of confidentiality. If the same code path is used to     compute the authentication tag, the tag depends only on the (key, IV) pair and not on the plaintext or     ciphertext, allowing universal forgery of arbitrary ciphertext from a single captured message. OpenSSL     provides two ways to drive a cipher: the documented streaming interface (EVP_CipherUpdate /     EVP_CipherFinal_ex) and a lower-level one-shot, EVP_Cipher(), whose documentation explicitly recommends     against use by applications in favour of EVP_CipherUpdate() and EVP_CipherFinal_ex(). The OCB provider's     streaming handler flushes the application-supplied IV into the OCB context before processing data; the     one-shot handler did not. Every call to EVP_Cipher() on an AES-OCB context therefore ran with the all-zero     key-derived offset state left by cipher initialisation, regardless of the caller's IV. If     EVP_EncryptFinal_ex() is subsequently used to obtain the authentication tag, the deferred IV setup runs at     that point and clears the running checksum that should have been accumulated over the plaintext. The     resulting tag is a function of (key, IV) only and verifies against any ciphertext produced under the same     (key, IV) pair. The OpenSSL SSL/TLS implementation is not affected: AES-OCB is not a TLS cipher suite, and     libssl does not call EVP_Cipher() in any case. Applications that drive AES-OCB through the documented     streaming AEAD API (EVP_CipherUpdate / EVP_CipherFinal_ex) are not affected. Only applications that     combine the AES-OCB cipher with the EVP_Cipher() one-shot API are vulnerable. The FIPS modules in 4.0,     3.6, 3.5, 3.4 and 3.0 are not affected by this issue, as AES-OCB is outside the OpenSSL FIPS module     boundary. (CVE-2026-45445)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
320403	Ubuntu 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS : OpenSSL vulnerabilities (USN-8414-1)	Nessus	Ubuntu Local Security Checks	critical
320327	Linux Distros Unpatched Vulnerability : CVE-2026-7383	Nessus	Misc.	high
320216	Debian dsa-6335 : libcrypto3-udeb - security update	Nessus	Debian Local Security Checks	critical
320142	OpenSSL 3.0.0 < 3.0.21 Multiple Vulnerabilities	Nessus	Web Servers	critical
320141	OpenSSL 1.0.2 < 1.0.2zq Multiple Vulnerabilities	Nessus	Web Servers	critical
320140	OpenSSL 4.0.0 < 4.0.1 Multiple Vulnerabilities	Nessus	Web Servers	critical
320139	OpenSSL 1.1.1 < 1.1.1zh Multiple Vulnerabilities	Nessus	Web Servers	critical
320138	OpenSSL 3.4.0 < 3.4.6 Multiple Vulnerabilities	Nessus	Web Servers	critical
320136	OpenSSL 3.5.0 < 3.5.7 Multiple Vulnerabilities	Nessus	Web Servers	critical
320135	OpenSSL 3.6.0 < 3.6.3 Multiple Vulnerabilities	Nessus	Web Servers	critical

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