CVE-2026-56211

Public on 2026-06-19
Modified on 2026-06-20
Description
A remote code execution vulnerability was found in libaom, the reference AV1 codec implementation. Insufficient bounds validation in the AV1 encoder's SVC (Scalable Video Coding) layer ID control allows an attacker to supply crafted video frame pixels that overlap with internal encoder layer context structures. In fork-based video processing services, an attacker can use this to hijack the cyclic refresh map pointer, brute-force the process base address via a crash oracle, and redirect control flow to achieve arbitrary command execution. Exploitation requires the target service to use libaom with SVC encoding enabled and accept attacker-supplied video frames.
Severity
Important severity
Important
See what this means
CVSS v3 Base Score
7.5
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 7.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H