Description NGINX JavaScript (njs) has a vulnerability in the XML module's namespace prefix list parser, reachable through the xml.exclusiveC14n() method. An unauthenticated remote attacker can trigger it when an affected NGINX configuration passes an externally controlled XML namespace prefix list to that method. Both the njs and the QuickJS (qjs) engines are affected. A crafted prefix list causes an out-of-bounds write past the end of a heap allocation. With the njs engine, which is the engine used when the js_engine directive is absent, this corrupts adjacent objects and crashes the NGINX worker. With the QuickJS engine, the same call additionally leaks the prefix list on every invocation, causing worker memory to grow across requests. The official nginxinc/nginx-saml reference implementation is affected during SAML signature verification. It reads InclusiveNamespaces/@PrefixList from an untrusted SAML message and passes it to xml.exclusiveC14n() before the signature has been verified, so a valid SAML signature is not required. A crafted SAML Response, Assertion, LogoutRequest, or LogoutResponse is sufficient. Code execution has not been demonstrated and cannot be ruled out for all platforms, as the effect of the out-of-bounds write depends on conditions beyond the attacker's control. Impact This vulnerability allows remote attackers to cause a denial of service on the NGINX system, either through repeatable worker restarts or through worker memory growth or possibly trigger code execution. There is no control plane exposure; this is a data plane issue only. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the 6cf326a2-b38c-11f1-a655-3497f65b111b advisory.

    The njs development team reports:
    Access control bypass in js_access when an asynchronous request                 body continuation threw an exception or produced an unhandled                 rejection (CVE-2026-18329).  Previously, nginx could continue                 processing the request as though the js_access check had                 succeeded.  Affects 0.9.9-1.0.0.
    Worker process crash when reading Response.statusText after an                 upstream server returned a status line with an empty reason                 phrase (CVE-2026-78222).  Affects 0.5.1-1.0.0.
    Heap buffer overflow while parsing namespace prefix lists                 passed to xml.exclusiveC14n() (CVE-2026-78689).  Affects                 0.7.10-1.0.0.

Tenable has extracted the preceding description block directly from the FreeBSD 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 FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the 0bfb082c-a7b6-11f1-a655-3497f65b111b advisory.

    F5 reports:
    A flaw in the NGINX JavaScript XML module allows an                 out-of-bounds write when xml.exclusiveC14n() processes a                 crafted XML namespace prefix list.  This may lead to worker                 process crashes, heap corruption or memory disclosure.  The                 NGINX SAML reference implementation is affected because it                 processes SAML data before signature verification.

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.

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

  - Description NGINX JavaScript (njs) has a vulnerability in the XML module's namespace prefix list parser,     reachable through the xml.exclusiveC14n() method. An unauthenticated remote attacker can trigger it when     an affected NGINX configuration passes an externally controlled XML namespace prefix list to that method.
    Both the njs and the QuickJS (qjs) engines are affected. A crafted prefix list causes an out-of-bounds     write past the end of a heap allocation. With the njs engine, which is the engine used when the js_engine     directive is absent, this corrupts adjacent objects and crashes the NGINX worker. With the QuickJS engine,     the same call additionally leaks the prefix list on every invocation, causing worker memory to grow across     requests. The official nginxinc/nginx-saml reference implementation is affected during SAML signature     verification. It reads InclusiveNamespaces/@PrefixList from an untrusted SAML message and passes it to     xml.exclusiveC14n() before the signature has been verified, so a valid SAML signature is not required. A     crafted SAML Response, Assertion, LogoutRequest, or LogoutResponse is sufficient. Code execution has not     been demonstrated and cannot be ruled out for all platforms, as the effect of the out-of-bounds write     depends on conditions beyond the attacker's control. Impact This vulnerability allows remote attackers to     cause a denial of service on the NGINX system, either through repeatable worker restarts or through worker     memory growth or possibly trigger code execution. There is no control plane exposure; this is a data plane     issue only. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
    (CVE-2026-78689)

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

ID	Name	Product	Family	Type	Severity
349287	FreeBSD : angie-module-njs -- multiple vulnerabilities (6cf326a2-b38c-11f1-a655-3497f65b111b)	Nessus	FreeBSD Local Security Checks	Local	critical
342830	FreeBSD : njs -- heap buffer overflow in XML exclusive canonicalization (0bfb082c-a7b6-11f1-a655-3497f65b111b)	Nessus	FreeBSD Local Security Checks	Local	critical
342607	Linux Distros Unpatched Vulnerability : CVE-2026-78689	Nessus	Misc.	Local	critical

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