xmlwf in libexpat before 2.8.2 has an integer overflow in resolveSystemId.

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - libexpat before 2.8.2 does not consider XML_TOK_DATA_CHARS in doCdataSection and thus lacks handler call
    depth tracking for various calls from within handlers in cases of a policy violation. Thus, a use-after-
    free can occur. NOTE: this issue exists because of an incomplete fix for CVE-2026-50219. (CVE-2026-56412)

  - libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_GetBuffer, XML_Parse,
    XML_ParseBuffer, XML_ParserFree, or XML_ParserReset from within handlers in cases of a policy violation.
    Thus, a use-after-free can occur, (CVE-2026-50219)

  - libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_ResumeParser from within handlers
    in cases of a policy violation. Thus, a use-after-free can occur (similar to the CVE-2026-50219
    situation). (CVE-2026-56131)

  - In libexpat before 2.8.2, there is a heap-based buffer overflow in doProlog in xmlparse.c because scaffold
    backing array reallocation is mishandled when there is data-structure sharing across parsers.
    (CVE-2026-56132)

  - libexpat before 2.8.2 has an integer overflow in storeAtts. (CVE-2026-56403)

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 d06b1fa2-731f-11f1-a0d2-589cfc10a551 advisory.

    Expat 2.8.2 was released yesterday. The key motivation for cutting a release and doing so now was     getting security and non-security bugsfixes out to users. On the security side,     13 vulnerabilities have been fixed:

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

  - xmlwf in libexpat before 2.8.2 has an integer overflow in resolveSystemId. (CVE-2026-56410)

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

ID	Name	Product	Family	Severity
444103	Alpine: libexpat, multiple expat packages: security update to 2.8.2-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	medium
444103	Alpine: libexpat, multiple expat packages: security update to 2.8.2-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	medium
323688	FreeBSD : Multiple vulnerability found in Expat (d06b1fa2-731f-11f1-a0d2-589cfc10a551)	Nessus	FreeBSD Local Security Checks	medium
321890	Linux Distros Unpatched Vulnerability : CVE-2026-56410	Nessus	Misc.	medium

Detections

Analytics

CVE-2026-56410

medium

Tenable Plugins

medium

medium

medium

medium