Successfully using libcurl to do a transfer over a specific HTTP proxy (`proxyA`) with **Digest** authentication and then changing the proxy host to a second one (`proxyB`) for a second transfer, reusing the same handle, makes libcurl wrongly pass on the `Proxy-Authorization:` header field meant for `proxyA`, to `proxyB`.

The version of AOS installed on the remote host is prior to 7.6. It is, therefore, affected by multiple vulnerabilities as referenced in the NXSA-AOS-7.6 advisory.

  - NLnet Labs Unbound 1.19.1 up to and including version 1.25.0 has a vulnerability in the DNSSEC validator     that enables denial of service and possible remote code execution as a result of deep copying a data     structure and erroneously overwriting a destination pointer. An adversary can exploit the vulnerability by     controlling a malicious signed zone and querying a vulnerable Unbound. When DS sub-queries need to suspend     validation due to NSEC3 computational budget exhaustion (introduced in Unbound 1.19.1), Unbound deep-     copies response messages to preserve them across memory region teardown. A struct-assignment bug     overwrites the destination's pointer with the source's pointer. After the sub-query region is freed, the     resumed validator dereferences this dangling pointer, triggering a crash or potentially enabling arbitrary     code execution. Unbound 1.25.1 contains a patch with a fix to preserve the correct pointer when deep     copying the data structure. (CVE-2026-33278)

  - A vulnerability has been found in GNU Binutils 2.45. The affected element is the function elf_swap_shdr in     the library bfd/elfcode.h of the component Linker. The manipulation leads to heap-based buffer overflow.
    The attack must be carried out locally. The exploit has been disclosed to the public and may be used. The     identifier of the patch is 9ca499644a21ceb3f946d1c179c38a83be084490. To fix this issue, it is recommended     to deploy a patch. The code maintainer replied with [f]ixed for 2.46. (CVE-2025-11083)

  - A heap-based buffer overflow problem was found in glib through an incorrect calculation of buffer size in     the g_escape_uri_string() function. If the string to escape contains a very large number of unacceptable     characters (which would need escaping), the calculation of the length of the escaped string could     overflow, leading to a potential write off the end of the newly allocated string. (CVE-2025-13601)

  - Vim is an open source, command line text editor. Prior to version 9.1.1552, a path traversal issue in     Vim's tar.vim plugin can allow overwriting of arbitrary files when opening specially crafted tar archives.
    Impact is low because this exploit requires direct user interaction. However, successfully exploitation     can lead to overwriting sensitive files or placing executable code in privileged locations, depending on     the permissions of the process editing the archive. The victim must edit such a file using Vim which will     reveal the filename and the file content, a careful user may suspect some strange things going on.
    Successful exploitation could results in the ability to execute arbitrary commands on the underlying     operating system. Version 9.1.1552 contains a patch for the vulnerability. (CVE-2025-53905)

  - Vim is an open source, command line text editor. Prior to version 9.1.1551, a path traversal issue in     Vim's zip.vim plugin can allow overwriting of arbitrary files when opening specially crafted zip archives.
    Impact is low because this exploit requires direct user interaction. However, successfully exploitation     can lead to overwriting sensitive files or placing executable code in privileged locations, depending on     the permissions of the process editing the archive. The victim must edit such a file using Vim which will     reveal the filename and the file content, a careful user may suspect some strange things going on.
    Successful exploitation could results in the ability to execute arbitrary commands on the underlying     operating system. Version 9.1.1551 contains a patch for the vulnerability. (CVE-2025-53906)

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

According to the versions of the  packages installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities :

    Using libcurl, when a custom `Host:` header is first set for an HTTP request and a second request is     subsequently done using the same *easy handle* but without the custom `Host:` header set, the second     request would use stale information and pass on cookies meant for the first host in the second request.
    Leak them.(CVE-2026-6276)

    libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated HTTP(S)     request after a Negotiate-authenticated one, when both use the same host. libcurl features a pool of     recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When     reusing a connection a range of criteria must be met. Due to a logical error in the code, a request that     was issued by an application could wrongfully reuse an existing connection to the same server that was     authenticated using different credentials. An application that first uses Negotiate authentication to a     server with `user1:password1` and then does another operation to the same server asking for any     authentication method but for `user2:password2` (while the previous connection is still alive) - the     second request gets confused and wrongly reuses the same connection and sends the new request over that     connection thinking it uses a mix of user1's and user2's credentials when it is in fact still using the     connection authenticated for user1...(CVE-2026-5545)

    curl might erroneously pass on credentials for a first proxy to a second proxy. This can happen when the     following conditions are true: 1. curl is setup to use specific different proxies for different URL     schemes 2. the first proxy needs credentials 3. the second proxy uses no credentials 4. while using the     first proxy (using say `http://`), curl is asked to follow a redirect to a URL using another scheme (say     `https://`), accessed using a second, different, proxy(CVE-2026-6253)

    libcurl might in some circumstances reuse the wrong connection for SMB(S) transfers. libcurl features a     pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead.
    When reusing a connection a range of criteria must be met. Due to a logical error in the code, a network     transfer operation that was requested by an application could wrongfully reuse an existing SMB connection     to the same server that was using a different 'share' than the new subsequent transfer should. This could     in unlucky situations lead to the download of the wrong file or the upload of a file to the wrong place.
    When this happens, the same credentials are used and the server name is the same.(CVE-2026-5773)

    A vulnerability exists where a connection requiring TLS incorrectly reuses an existing unencrypted     connection from the same connection pool. If an initial transfer is made in clear-text (via IMAP, SMTP, or     POP3), a subsequent request to that same host bypasses the TLS requirement and instead transmit data     unencrypted.(CVE-2026-4873)

    When asked to both use a `.netrc` file for credentials and to follow HTTP redirects, libcurl could leak     the password used for the first host to the followed-to host under certain circumstances.(CVE-2026-6429)

    Successfully using libcurl to do a transfer over a specific HTTP proxy (`proxyA`) with **Digest**     authentication and then changing the proxy host to a second one (`proxyB`) for a second transfer, reusing     the same handle, makes libcurl wrongly pass on the `Proxy-Authorization:` header field meant for `proxyA`,     to `proxyB`.(CVE-2026-7168)

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

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

According to the versions of the curl packages installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities :

    Using libcurl, when a custom `Host:` header is first set for an HTTP request and a second request is     subsequently done using the same *easy handle* but without the custom `Host:` header set, the second     request would use stale information and pass on cookies meant for the first host in the second request.
    Leak them.(CVE-2026-6276)

    libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated HTTP(S)     request after a Negotiate-authenticated one, when both use the same host. libcurl features a pool of     recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When     reusing a connection a range of criteria must be met. Due to a logical error in the code, a request that     was issued by an application could wrongfully reuse an existing connection to the same server that was     authenticated using different credentials. An application that first uses Negotiate authentication to a     server with `user1:password1` and then does another operation to the same server asking for any     authentication method but for `user2:password2` (while the previous connection is still alive) - the     second request gets confused and wrongly reuses the same connection and sends the new request over that     connection thinking it uses a mix of user1's and user2's credentials when it is in fact still using the     connection authenticated for user1...(CVE-2026-5545)

    curl might erroneously pass on credentials for a first proxy to a second proxy. This can happen when the     following conditions are true: 1. curl is setup to use specific different proxies for different URL     schemes 2. the first proxy needs credentials 3. the second proxy uses no credentials 4. while using the     first proxy (using say `http://`), curl is asked to follow a redirect to a URL using another scheme (say     `https://`), accessed using a second, different, proxy(CVE-2026-6253)

    libcurl might in some circumstances reuse the wrong connection for SMB(S) transfers. libcurl features a     pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead.
    When reusing a connection a range of criteria must be met. Due to a logical error in the code, a network     transfer operation that was requested by an application could wrongfully reuse an existing SMB connection     to the same server that was using a different 'share' than the new subsequent transfer should. This could     in unlucky situations lead to the download of the wrong file or the upload of a file to the wrong place.
    When this happens, the same credentials are used and the server name is the same.(CVE-2026-5773)

    A vulnerability exists where a connection requiring TLS incorrectly reuses an existing unencrypted     connection from the same connection pool. If an initial transfer is made in clear-text (via IMAP, SMTP, or     POP3), a subsequent request to that same host bypasses the TLS requirement and instead transmit data     unencrypted.(CVE-2026-4873)

    When asked to both use a `.netrc` file for credentials and to follow HTTP redirects, libcurl could leak     the password used for the first host to the followed-to host under certain circumstances.(CVE-2026-6429)

    Successfully using libcurl to do a transfer over a specific HTTP proxy (`proxyA`) with **Digest**     authentication and then changing the proxy host to a second one (`proxyB`) for a second transfer, reusing     the same handle, makes libcurl wrongly pass on the `Proxy-Authorization:` header field meant for `proxyA`,     to `proxyB`.(CVE-2026-7168)

Tenable has extracted the preceding description block directly from the EulerOS Virtualization curl 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 remote Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 24.04 LTS / 26.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8525-1 advisory.

    Harry Sintonen discovered that curl incorrectly handled credentials when following HTTP redirects in     conjunction with .netrc files. An attacker could possibly use this issue to obtain sensitive information.
    This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 18.04 LTS. (CVE-2024-11053)

    Hiroki Kurosawa discovered that curl incorrectly handled OCSP stapling responses. A remote attacker could     possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 16.04 LTS and     Ubuntu 18.04 LTS. (CVE-2024-8096)

    Joshua Rogers discovered that curl had a use-after-free vulnerability when resetting and cleaning up     HTTP/2 stream handles. An attacker could possibly use this issue to cause a denial of service or execute     arbitrary code. This issue only affected Ubuntu 24.04 LTS, Ubuntu 25.04, and Ubuntu 25.10.
    (CVE-2026-10536)

    Quac Tran and Ngoc Hieu discovered that curl incorrectly reused connections when switching authentication     methods to the same host. An attacker could possibly use this issue to obtain sensitive information or     perform unauthorized actions. This issue only affected Ubuntu 20.04 LTS. (CVE-2026-5545)

    Osama Hamad discovered that curl incorrectly reused SMB connections when the target share differed between     transfers. An attacker could possibly use this issue to obtain sensitive information. This issue only     affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-5773)

    Muhamad Arga Reksapati discovered that curl incorrectly forwarded Digest proxy authentication credentials     to a different proxy host. An attacker could possibly use this issue to obtain sensitive information. This     issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2026-7168)

    It was discovered that curl incorrectly skipped SSH host verification options when using schemeless URLs     with --proto-default. An attacker could possibly use this issue to perform machine-in-the-middle attacks.
    This issue only affected Ubuntu 25.04 and Ubuntu 25.10. (CVE-2026-12064)

    It was discovered that curl did not enforce an upper bound on memory allocated for unacknowledged     WebSocket PING frames. A remote attacker could possibly use this issue to cause a denial of service. This     issue only affected Ubuntu 25.10. (CVE-2026-11586)

    It was discovered that curl could stall indefinitely when a malicious HTTP/3 server sent a continuous     stream of empty UDP datagrams. A remote attacker could possibly use this issue to cause a denial of     service. This issue only affected Ubuntu 25.10. (CVE-2026-11352)

    It was discovered that curl could incorrectly continue trusting a native platform CA store after an     application switched the handle to use custom CA material. An attacker could possibly use this issue to     obtain sensitive information. This issue only affected Ubuntu 25.10. (CVE-2026-11564)

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.

According to the versions of the curl packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

    Using libcurl, when a custom `Host:` header is first set for an HTTP request     and a second request is subsequently done using the same *easy handle* but     without the custom `Host:` header set, the second request would use stale     information and pass on cookies meant for the first host in the second     request. Leak them.(CVE-2026-6276)

    libcurl might in some circumstances reuse the wrong connection when asked to     do an authenticated HTTP(S) request after a Negotiate-authenticated one, when     both use the same host.

    libcurl features a pool of recent connections so that subsequent requests can     reuse an existing connection to avoid overhead.

    When reusing a connection a range of criteria must be met. Due to a logical     error in the code, a request that was issued by an application could     wrongfully reuse an existing connection to the same server that was     authenticated using different credentials.

    An application that first uses Negotiate authentication to a server with     `user1:password1` and then does another operation to the same server asking     for any authentication method but for `user2:password2` (while the previous     connection is still alive) - the second request gets confused and wrongly     reuses the same connection and sends the new request over that connection     thinking it uses a mix of user1's and user2's credentials when it is in fact     still using the connection authenticated for user1...(CVE-2026-5545)

    curl might erroneously pass on credentials for a first proxy to a second     proxy.

    This can happen when the following conditions are true:

    1. curl is setup to use specific different proxies for different URL schemes     2. the first proxy needs credentials     3. the second proxy uses no credentials     4. while using the first proxy (using say `http://`), curl is asked to follow        a redirect to a URL using another scheme (say `https://`), accessed using a        second, different, proxy(CVE-2026-6253)

    libcurl might in some circumstances reuse the wrong connection for SMB(S)     transfers.

    libcurl features a pool of recent connections so that subsequent requests can     reuse an existing connection to avoid overhead.

    When reusing a connection a range of criteria must be met. Due to a logical     error in the code, a network transfer operation that was requested by an     application could wrongfully reuse an existing SMB connection to the same     server that was using a different 'share' than the new subsequent transfer     should.

    This could in unlucky situations lead to the download of the wrong file or the     upload of a file to the wrong place. When this happens, the same credentials     are used and the server name is the same.(CVE-2026-5773)

    A vulnerability exists where a connection requiring TLS incorrectly reuses an     existing unencrypted connection from the same connection pool. If an initial     transfer is made in clear-text (via IMAP, SMTP, or POP3), a subsequent request     to that same host bypasses the TLS requirement and instead transmit data     unencrypted.(CVE-2026-4873)

    When asked to both use a `.netrc` file for credentials and to follow HTTP     redirects, libcurl could leak the password used for the first host to the     followed-to host under certain circumstances.(CVE-2026-6429)

    Successfully using libcurl to do a transfer over a specific HTTP proxy     (`proxyA`) with **Digest** authentication and then changing the proxy host to     a second one (`proxyB`) for a second transfer, reusing the same handle, makes     libcurl wrongly pass on the `Proxy-Authorization:` header field meant for     `proxyA`, to `proxyB`.(CVE-2026-7168)

Tenable has extracted the preceding description block directly from the EulerOS curl 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 Tenable Identity Exposure running on the remote host is prior to 3.93.5. It is, therefore, affected by multiple vulnerabilities according to advisory TNS-2026-16:

  - Tenable Identity Exposure contains multiple unauthenticated API endpoints under /w/api/* that expose     sensitive application configuration data including cleartext LDAP credentials, SAML configuration, user     accounts, and directory settings to unauthenticated remote attackers. Affected responses are served with     Cache-Control: public headers and without Vary: Cookie, allowing reverse proxies and CDNs to cache and     serve sensitive data to unauthenticated users even after authentication is applied. (CVE-2026-13007)

  - Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows     an authorized attacker to bypass a security feature over a network. (CVE-2025-55315)

  - Converting an excessively large OCTET STRING value to a hexadecimal string leads to a heap buffer     overflow on 32 bit platforms. A heap buffer overflow may lead to a crash or possibly an attacker     controlled code execution or other undefined behavior. (CVE-2026-31789)

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

An update of the curl package has been released.

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-8227-1 advisory.

    It was discovered that curl incorrectly reused non-TLS connections when TLS was required in some STARTTLS     configurations. A remote attacker could possibly use this issue to obtain sensitive information.
    (CVE-2026-4873)

    It was discovered that curl incorrectly reused certain HTTP Negotiate connections. A remote attacker could     possibly use this issue to obtain sensitive information. (CVE-2026-5545)

    It was discovered that curl incorrectly reused certain SMB connections. A remote attacker could possibly     use this issue to obtain sensitive information. (CVE-2026-5773)

    It was discovered that curl could leak proxy credentials when handling redirects in some configurations. A     remote attacker could possibly use this issue to obtain sensitive information. (CVE-2026-6253)

    It was discovered that curl could leak cookies because of stale custom cookie host handling in some     requests. A remote attacker could possibly use this issue to obtain sensitive information. (CVE-2026-6276)

    It was discovered that curl could leak .netrc credentials when reusing proxy connections in some     situations. A remote attacker could possibly use this issue to obtain sensitive information.
    (CVE-2026-6429)

    It was discovered that curl could leak Digest authentication state when switching proxies in some     situations. A remote attacker could possibly use this issue to obtain sensitive information.
    (CVE-2026-7168)

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 version of libcurl installed on the remote host is 7.12.0 prior to 8.20.0. It is, therefore, affected by a cross-proxy digest auth state leak vulnerability:

  - libcurl improperly handles Digest authentication headers when reusing handles across different HTTP     proxies. When a client switches from one proxy to another using the same connection handle, the     library incorrectly forwards the Proxy-Authorization header intended for the first proxy to the     second one. An evil proxyB could use this incoming request header field to impersonate the client     in communicating with proxyA, as the header contains the authenticated state. (CVE-2026-7168)

Note that Nessus has not tested for this issue 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.

  - Successfully using libcurl to do a transfer over a specific HTTP proxy (`proxyA`) with **Digest**     authentication and then changing the proxy host to a second one (`proxyB`) for a second transfer, reusing     the same handle, makes libcurl wrongly pass on the `Proxy-Authorization:` header field meant for `proxyA`,     to `proxyB`. (CVE-2026-7168)

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

ID	Name	Product	Family	Severity
328839	Nutanix AOS : Multiple Vulnerabilities (NXSA-AOS-7.6)	Nessus	Misc.	critical
328617	EulerOS Virtualization 2.12.1 (EulerOS-SA-2026-2723)	Nessus	Huawei Local Security Checks	high
328523	EulerOS Virtualization 2.12.0 : curl (EulerOS-SA-2026-2769)	Nessus	Huawei Local Security Checks	high
326253	Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 24.04 LTS / 26.04 LTS : curl vulnerabilities (USN-8525-1)	Nessus	Ubuntu Local Security Checks	high
326141	EulerOS 2.0 SP12 : curl (EulerOS-SA-2026-2523)	Nessus	Huawei Local Security Checks	high
326110	EulerOS 2.0 SP12 : curl (EulerOS-SA-2026-2583)	Nessus	Huawei Local Security Checks	high
322483	Tenable Identity Exposure < 3.93.5 Multiple Vulnerabilities (TNS-2026-16)	Nessus	Misc.	high
318364	Photon OS 5.0: Curl PHSA-2026-5.0-0856	Nessus	PhotonOS Local Security Checks	medium
315300	Photon OS 4.0: Curl PHSA-2026-4.0-1020	Nessus	PhotonOS Local Security Checks	medium
312298	Ubuntu 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS : curl vulnerabilities (USN-8227-1)	Nessus	Ubuntu Local Security Checks	high
311422	libcurl 7.12.0 < 8.20.0 Cross-Proxy Digest Auth State Leak	Nessus	Misc.	medium
310991	Linux Distros Unpatched Vulnerability : CVE-2026-7168	Nessus	Misc.	medium

Detections

Analytics

CVE-2026-7168

medium

Tenable Plugins

critical

high

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high

high

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medium

medium

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medium

medium