CVE-2026-56131

NameCVE-2026-56131
Descriptionlibexpat 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).
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs1140387

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
expat (PTS)bullseye2.2.10-2+deb11u5vulnerable
bullseye (security)2.2.10-2+deb11u7vulnerable
bookworm2.5.0-1+deb12u2vulnerable
bookworm (security)2.5.0-1+deb12u1vulnerable
trixie2.7.1-2vulnerable
forky, sid2.8.2-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
expatsource(unstable)2.8.2-11140387

Notes

https://github.com/libexpat/libexpat/pull/1267
Search for package or bug name: Reporting problems