CVE-2026-56412

Name	CVE-2026-56412
Description	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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
expat (PTS)	bullseye	2.2.10-2+deb11u5	vulnerable
	bullseye (security)	2.2.10-2+deb11u7	vulnerable
	bookworm	2.5.0-1+deb12u2	vulnerable
	bookworm (security)	2.5.0-1+deb12u1	vulnerable
	trixie	2.7.1-2	vulnerable
	forky, sid	2.8.1-1	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
expat	source	(unstable)	(unfixed)

https://github.com/libexpat/libexpat/pull/1278
Fixed by: https://github.com/libexpat/libexpat/commit/d19e834794060d18c061d94452c35d725393ea58