Improper Following of a Certificate's Chain of Trust vulnerability in Erlang OTP public_key (pubkey_cert module) allows a non-CA certificate to be accepted as an intermediate issuer, enabling certificate chain forgery. In lib/public_key/src/pubkey_cert.erl, pubkey_cert:validate_extensions/7 contains two flaws that together allow a certificate with basicConstraints cA:false and no keyUsage extension to be used as an intermediate issuer in a chain passed to public_key:pkix_path_validation/3: the cA:false clause recurses into the remaining extensions without rejecting the certificate when it is in issuer position, and the keyUsage check only fires when the extension is present, so a certificate lacking keyUsage entirely bypasses the keyCertSign enforcement. Any party holding an end-entity certificate with basicConstraints cA:false and no keyUsage extension, issued by any CA in the victim's trust store, can use that certificate's private key to sign forged leaf certificates for arbitrary identities. public_key:pkix_path_validation/3 accepts the resulting chain, and by extension every TLS or mTLS endpoint built on the OTP ssl application that relies on the default verifier is affected, including server identity verification on the client side and client certificate verification on mTLS servers. This issue affects OTP from OTP 17.0 before OTP 29.0.1, OTP 28.5.0.1, OTP 27.3.4.12 and OTP 26.2.5.21, corresponding to public_key from 0.22 before 1.21.1, 1.20.3.1, 1.17.1.3 and 1.15.1.7.

The remote SUSE Linux SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:3645-1 advisory.

    - CVE-2026-28810: predictable DNS transaction IDs can cause DNS cache poisoning (bsc#1261726).
    - CVE-2026-42789: `public_key` application accepts non-CA certificates as intermediate issuers and this     enables chain       forgery (bsc#1266449).
    - CVE-2026-42790: Name constraints and `Subject CommonName` fallback in TLS hostname verification allows     for certificate       forgery by MITM attacker (bsc#1266466).
    - CVE-2026-42792: permanent `epmd` DoS via connection slot exhaustion due to improper handling of     exceptional       conditions (bsc#1272908).
    - CVE-2026-47078: relative path traversal in `zip:unzip/zip:extract` via `check_dir_level` depth-counter     bypass       (bsc#1272909).
    - CVE-2026-48855: SFTP `READLINK` response leaks absolute backend filesystem path when root is configured     (bsc#1268139).
    - CVE-2026-48856: `httpc` leaks `Authorization` headers to cross-origin redirect targets (bsc#1268141).
    - CVE-2026-48858: server-side request forgery allows FTP bounce attacks and SSRF via an unvalidated `PASV`     response IP       address (bsc#1268142).
    - CVE-2026-49759: unbounded stack buffer overflow in SCTP error cause parsing in `inet_drv` (bsc#1268163).
    - CVE-2026-49760: stack buffer overflow in `ei_s_print_term` at very large integer (bsc#1268164).
    - CVE-2026-53422: SFTP `REALPATH` path-existence oracle allows filesystem enumeration outside configured     root       (bsc#1270245).
    - CVE-2026-54886: SSH SFTP server denial of service via extended channel data infinite loop (bsc#1270246).
    - CVE-2026-54887: use of default cryptographic key allows predictable DTLS cookie computation during the     startup window       (bsc#1270247).
    - CVE-2026-54891: plaintext injection towards (D)TLS client during handshake (bsc#1270250).
    - CVE-2026-55737: heap pointer corruption via signed/unsigned mismatch in `LARGE_TUPLE_EXTP` decoding in     `erts`       external term format decoder (bsc#1272910).
    - CVE-2026-55952: missing validation allows for DoS of the TLS-1.3 server when clients send a malformed     `ClientHello`       with mismatched PSK identity and binder list lengths (bsc#1270258).
    - CVE-2026-55953: TLS 1.2 and DTLS clients accept unoffered anonymous cipher suites and allow for server     authentication       bypass (bsc#1272911).
    - CVE-2026-58227: TLS/DTLS denial of service via unbounded recursion on cross-signed peer certificate     chain       (bsc#1272913).
    - CVE-2026-59250: `megaco` flex scanner buffer overflow via oversized property parm name (bsc#1272914).

Tenable has extracted the preceding description block directly from the SUSE 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 Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:54757 advisory.

    Red Hat OpenStack Platform provides the facilities for building, deploying and monitoring a private or     public infrastructure-as-a-service (IaaS) cloud running on commonly available physical hardware.

    Security Fix(es):

    * crypto/x509: golang: Denial of Service due to excessive resource consumption via crafted certificate     (CVE-2025-61729)

    * openstack-nova-compute: Arbitrary Host File Overwrite via Unconstrained qemu-img Format Handling in     OpenStack Nova (CVE-2026-24708)

    * pyasn1: pyasn1: Denial of Service due to memory exhaustion from malformed RELATIVE-OID (CVE-2026-23490)

    * golang: net/url: Memory exhaustion in query parameter parsing in net/url (CVE-2025-61726)

    * crypto/tls: crypto/tls: Incorrect certificate validation during TLS session resumption (CVE-2025-68121)

    * openstack-glance: OpenStack Glance: Server-Side Request Forgery leading to unauthorized internal network     access (CVE-2026-34881)

    * crypto/x509: Incorrect enforcement of email constraints in crypto/x509 (CVE-2026-27137)

    * net/url: Incorrect parsing of IPv6 host literals in net/url (CVE-2026-25679)

    * google.golang.org/grpc/grpc-go: google.golang.org/grpc/authz: gRPC-Go: Authorization bypass due to     improper HTTP/2 path validation (CVE-2026-33186)

    * etcd: etcd: Authorization bypass allows information disclosure and denial of service (CVE-2026-33413)

    * crypto/x509: golang: Go crypto/x509: Denial of Service via inefficient certificate chain validation     (CVE-2026-32281)

    * crypto/x509: golang: Go crypto/x509: Certificate validation bypass due to incorrect DNS constraint     application (CVE-2026-33810)

    * golang: internal/syscall/unix: Root.Chmod can follow symlinks out of the root (CVE-2026-32282)

    * crypto/tls: golang: Go crypto/tls: Denial of Service via multiple TLS 1.3 key update messages     (CVE-2026-32283)

    * crypto/x509: crypto/tls: golang: Go: Denial of Service vulnerability in certificate chain building     (CVE-2026-32280)

    * net: golang: Go net package: Denial of Service via long CNAME response in LookupCNAME (CVE-2026-33811)

    * golang.org/x/net/idna: golang: net/http: golang.org/x/net/idna: Privilege escalation via incorrect     Punycode label processing (CVE-2026-39821)

    * erlang: Erlang OTP public_key: Certificate chain forgery via improper trust chain validation     (CVE-2026-42789)

    * crypto/x509: golang: golang crypto/x509: Denial of Service via excessive processing of DNS SAN entries     (CVE-2026-27145)

    * oslo.messaging: openstack: OpenStack oslo.messaging: Man-in-the-middle attack via improper TLS hostname     verification (CVE-2026-44393)

    * erlang: Erlang OTP public_key: Certificate validation bypass allows hostname spoofing (CVE-2026-42790)

    * openstack-keystone: OpenStack Keystone: Unauthorized access and privilege escalation via AWS signature     validation flaw (CVE-2025-65073)

    * OpenStack Keystone: OpenStack Keystone: Unauthorized cross-project access due to improper validation in     EC2 credential creation (CVE-2026-43001)

    * openstack-keystone: OpenStack Keystone: Privilege escalation through EC2 credential creation     (CVE-2026-33551)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux 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 SUSE Linux SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:3579-1 advisory.

    - CVE-2026-28810: predictable DNS transaction IDs can cause DNS cache poisoning (bsc#1261726).
    - CVE-2026-42789: `public_key` application accepts non-CA certificates as intermediate issuers and this     enables chain       forgery (bsc#1266449).
    - CVE-2026-42790: Name constraints and `Subject CommonName` fallback in TLS hostname verification allows     for certificate       forgery by MITM attacker (bsc#1266466).
    - CVE-2026-42792: permanent `epmd` DoS via connection slot exhaustion due to improper handling of     exceptional       conditions (bsc#1272908).
    - CVE-2026-47078: relative path traversal in `zip:unzip/zip:extract` via `check_dir_level` depth-counter     bypass       (bsc#1272909).
    - CVE-2026-48855: SFTP `READLINK` response leaks absolute backend filesystem path when root is configured     (bsc#1268139).
    - CVE-2026-48856: `httpc` leaks `Authorization` headers to cross-origin redirect targets (bsc#1268141).
    - CVE-2026-48858: server-side request forgery allows FTP bounce attacks and SSRF via an unvalidated `PASV`     response IP       address (bsc#1268142).
    - CVE-2026-48860: `ssl` (`inet_tls_dist` module) allows unauthenticated bypass of the distribution-over-     TLS LAN       allowlist (bsc#1268146).
    - CVE-2026-49759: unbounded stack buffer overflow in SCTP error cause parsing in `inet_drv` (bsc#1268163).
    - CVE-2026-49760: stack buffer overflow in `ei_s_print_term` at very large integer (bsc#1268164).
    - CVE-2026-53422: SFTP `REALPATH` path-existence oracle allows filesystem enumeration outside configured     root       (bsc#1270245).
    - CVE-2026-54886: SSH SFTP server denial of service via extended channel data infinite loop (bsc#1270246).
    - CVE-2026-54887: use of default cryptographic key allows predictable DTLS cookie computation during the     startup window       (bsc#1270247).
    - CVE-2026-54891: plaintext injection towards (D)TLS client during handshake (bsc#1270250).
    - CVE-2026-55737: heap pointer corruption via signed/unsigned mismatch in `LARGE_TUPLE_EXTP` decoding in     `erts`       external term format decoder (bsc#1272910).
    - CVE-2026-55950: time-of-check time-of-use race condition allows an unauthenticated remote attacker to     crash all active       DTLS sessions on a listener (bsc#1270253).
    - CVE-2026-55952: missing validation allows for DoS of the TLS-1.3 server when clients send a malformed     `ClientHello`       with mismatched PSK identity and binder list lengths (bsc#1270258).
    - CVE-2026-55953: TLS 1.2 and DTLS clients accept unoffered anonymous cipher suites and allow for server     authentication       bypass (bsc#1272911).
    - CVE-2026-58227: TLS/DTLS denial of service via unbounded recursion on cross-signed peer certificate     chain       (bsc#1272913).
    - CVE-2026-59250: `megaco` flex scanner buffer overflow via oversized property parm name (bsc#1272914).
    - CVE-2026-59251: denial of service via exponential certificate policy tree growth in path validation     (bsc#1272915).

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

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 erlang package has been released.

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:39809 advisory.

    Erlang is a general-purpose programming language and runtime environment.
    Erlang has built-in support for concurrency, distribution and fault     tolerance. Erlang is used in several large telecommunication systems from     Ericsson.

    Security Fix(es):

    * Erlang OTP public_key: Certificate chain forgery via improper trust chain     validation (CVE-2026-42789)

    * Erlang OTP public_key: Certificate validation bypass allows hostname     spoofing (CVE-2026-42790)

    For more details about the security issue(s), including the impact, a CVSS     score, acknowledgments, and other related information, refer to the CVE     page listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux 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.

The remote openSUSE 16 host has packages installed that are affected by multiple vulnerabilities as referenced in the openSUSE-SU-2026:20907-1 advisory.

    This update for erlang fixes the following issues

    - CVE-2025-4748: improper limitation of a pathname may lead to path traversal (bsc#1244642).
    - CVE-2026-32147: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in SFTP     chroot       (bsc#1262503).
    - CVE-2026-42789: `public_key` application accepts non-CA certificates as intermediate issuers and this     enables chain       forgery (bsc#1266449).
    - CVE-2026-42790: Name Constraints and Subject CommonName fallback in TLS hostname verification allows for     certificate       forgery by MITM attacker (bsc#1266466).
    - CVE-2026-42791: OCSP response verification in the `public_key` application does not check the validity     period of the       OCSP responder certificate and allows for OCSP response response forgery (bsc#1266448).

Tenable has extracted the preceding description block directly from the SUSE 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 Erlang/OTP installed on the remote host is 17.0 prior to 26.2.5.21, 27.0 prior to 27.3.4.12, 28.0 prior to 28.5.0.1, or 29.0 prior to 29.0.1. It is, therefore, affected by a vulnerability:

  - Improper Following of a Certificate's Chain of Trust vulnerability in Erlang OTP public_key     (pubkey_cert module) allows a non-CA certificate to be accepted as an intermediate issuer,     enabling certificate chain forgery. (CVE-2026-42789)

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.

  - Improper Following of a Certificate's Chain of Trust vulnerability in Erlang OTP public_key (pubkey_cert     module) allows a non-CA certificate to be accepted as an intermediate issuer, enabling certificate chain     forgery. In lib/public_key/src/pubkey_cert.erl, pubkey_cert:validate_extensions/7 contains two flaws that     together allow a certificate with basicConstraints cA:false and no keyUsage extension to be used as an     intermediate issuer in a chain passed to public_key:pkix_path_validation/3: the cA:false clause recurses     into the remaining extensions without rejecting the certificate when it is in issuer position, and the     keyUsage check only fires when the extension is present, so a certificate lacking keyUsage entirely     bypasses the keyCertSign enforcement. Any party holding an end-entity certificate with basicConstraints     cA:false and no keyUsage extension, issued by any CA in the victim's trust store, can use that     certificate's private key to sign forged leaf certificates for arbitrary identities.
    public_key:pkix_path_validation/3 accepts the resulting chain, and by extension every TLS or mTLS endpoint     built on the OTP ssl application that relies on the default verifier is affected, including server     identity verification on the client side and client certificate verification on mTLS servers. This issue     affects OTP from OTP 17.0 before OTP 29.0.1, OTP 28.5.0.1, OTP 27.3.4.12 and OTP 26.2.5.21, corresponding     to public_key from 0.22 before 1.21.1, 1.20.3.1, 1.17.1.3 and 1.15.1.7. (CVE-2026-42789)

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

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the 9357a450-5a54-11f1-b886-4c526214c986 advisory.

    https://github.com/erlang/otp/security/advisories/GHSA-c99q-jmpx-v8qq reports:
    Erlang/OTP's public_key application contains a               path-validation flaw where non-CA certificates lacking               keyUsage extensions can be accepted as intermediate issuers.
              An attacker with an end-entity certificate issued by a               trusted CA can exploit this to forge arbitrary leaf               certificates, allowing public_key:pkix_path_validation/3 to               validate fraudulent certificate chains and potentially               compromise systems relying on SSL/TLS validation.

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

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

ID	Name	Product	Family	Type	Severity
338632	SUSE SLES15 Security Update : erlang (SUSE-SU-2026:3645-1)	Nessus	SuSE Local Security Checks	Local	critical
335312	RHEL 8 : Red Hat OpenStack Platform 16.2 security advisory (Important) (RHSA-2026:54757)	Nessus	Red Hat Local Security Checks	Local	high
335097	SUSE SLES15 Security Update : erlang26 (SUSE-SU-2026:3579-1)	Nessus	SuSE Local Security Checks	Local	critical
333871	Photon OS 5.0: Erlang PHSA-2026-5.0-91-0883	Nessus	PhotonOS Local Security Checks	Local	high
326996	RHEL 9 : Red Hat OpenStack Services on OpenShift 18.0 (erlang) (RHSA-2026:39809)	Nessus	Red Hat Local Security Checks	Local	high
323235	Photon OS 4.0: Erlang PHSA-2026-4.0-1038	Nessus	PhotonOS Local Security Checks	Local	high
322483	Tenable Identity Exposure < 3.93.5 Multiple Vulnerabilities (TNS-2026-16)	Nessus	Misc.	Combined	high
321790	Photon OS 5.0: Erlang PHSA-2026-5.0-0883	Nessus	PhotonOS Local Security Checks	Local	high
320423	openSUSE 16 Security Update : erlang (openSUSE-SU-2026:20907-1)	Nessus	SuSE Local Security Checks	Local	high
317739	Erlang/OTP 17.0 < 26.2.5.21 / 27.0 < 27.3.4.12 / 28.0 < 28.5.0.1 / 29.0 < 29.0.1 Certificate Chain Forgery (CVE-2026-42789)	Nessus	Misc.	Local	high
317644	Linux Distros Unpatched Vulnerability : CVE-2026-42789	Nessus	Misc.	Local	high
317388	FreeBSD : Erlang/OTP -- public_key accepts non-CA certificate as intermediate issuer (9357a450-5a54-11f1-b886-4c526214c986)	Nessus	FreeBSD Local Security Checks	Local	high

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CVE-2026-42789

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Tenable Plugins

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