CVE-2026-56208

Public on 2026-06-19
Modified on 2026-06-20
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.
Severity
Important severity
Important
See what this means
CVSS v3 Base Score
7.6
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Firefox Extra firefox Pending Fix
Amazon Linux 2023 firefox Pending Fix
Amazon Linux 2 - Firefox Extra firefox-amzn-policies-generic Not Affected
Amazon Linux 2 - Core thunderbird Pending Fix

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 7.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H