CVE-2026-56208

Name	CVE-2026-56208
Description	A heap buffer overflow vulnerability was found in libaom, the reference AV1 codec implementation. A flaw in the AV1 encoder's Look-Ahead Processing (LAP) mode causes the first-pass stats ring buffer wrap-around guard to be bypassed when g_lag_in_frames is set to 1 or higher. This results in a 232-byte out-of-bounds write on every encoded frame after the second, corrupting adjacent heap objects. An attacker who can influence encoder configuration in a transcoding service or WebRTC session could exploit this to cause a denial of service (process crash) or potentially achieve code execution.
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-4774-1, DSA-6411-1
Debian Bugs	1140428

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
aom (PTS)	bookworm	3.6.0-1+deb12u2	vulnerable
	bookworm (security)	3.6.0-1+deb12u3	fixed
	trixie	3.12.1-1	vulnerable
	trixie (security)	3.12.1-1+deb13u1	fixed
	forky, sid	3.14.1-1	fixed

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

Package	Type	Release	Fixed Version	Origin	Debian Bugs
aom	source	bullseye	(not affected)
aom	source	bookworm	3.6.0-1+deb12u3	DLA-4774-1
aom	source	trixie	3.12.1-1+deb13u1	DSA-6411-1
aom	source	(unstable)	3.14.1-1		1140428

Notes

[bullseye] - aom <not-affected> (1.0.0 lacks LAP two-pass mode (encoder), introduced upstream in 2.0.0)
https://aomedia.googlesource.com/aom/+/243f8ae84bfbc495b3a3c12948abc4dff3af2f84
https://bugzilla.redhat.com/show_bug.cgi?id=2490799
https://issues.chromium.org/issues/504317456