CVE-2026-90783

Name	CVE-2026-90783
Description	MKVToolNix through 101.0 contains a heap buffer overflow in the bundled avilib library's ODML superindex parser due to integer wraparound in 32-bit arithmetic. Attackers can craft a malicious AVI file with oversized entry counts that cause an undersized heap allocation, allowing a heap buffer overflow when the file is parsed with mkvmerge.
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)
References	DLA-4805-1, DSA-6502-1
Debian Bugs	1147621

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
mkvtoolnix (PTS)	bookworm	74.0.0-1	vulnerable
	bookworm (security)	74.0.0-1+deb12u1	fixed
	trixie	92.0-1	vulnerable
	trixie (security)	92.0-1+deb13u1	fixed
	forky, sid	102.0-1	fixed

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

Package	Type	Release	Fixed Version	Origin	Debian Bugs
mkvtoolnix	source	bookworm	74.0.0-1+deb12u1	DLA-4805-1
mkvtoolnix	source	trixie	92.0-1+deb13u1	DSA-6502-1
mkvtoolnix	source	(unstable)	101.0-2		1147621

Notes

Fixed by: https://codeberg.org/mbunkus/mkvtoolnix/commit/1495126138e086080f0163bee27fafbdf956a1d0
Fixed by: https://codeberg.org/mbunkus/mkvtoolnix/commit/13fd81db3ae2b79d41536a9663719df11780797e