libaom EUVD-2026-38045

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.

libaom (AV1 reference codec implementation maintained at aomedia.googlesource.com/aom) is the directly affected upstream component; specific vulnerable version ranges were not enumerated in the provided data, but the fix is identified by upstream commit 243f8ae84b, and Red Hat tracks distribution-level exposure under access.redhat.com/security/cve/CVE-2026-56208 and bugzilla.redhat.com/show_bug.cgi?id=2490799. Downstream consumers that statically or dynamically link libaom - notably Chromium (issues.chromium.org/issues/504317456), Firefox, FFmpeg, GStreamer, and WebRTC media servers - should be considered transitively affected until they pick up a libaom build containing the patch commit.