CVE-2026-56211: aom Out-of-bounds Write

Vulnerability summary

CVE-2026-56211 is a high (CVSS 7.1) Out-of-bounds Write vulnerability in aom. EPSS estimates a 0.88% chance of exploitation in the next 30 days, higher than 58.3% of scored vulnerabilities.

Timeline

1. 19-06-2026
   PublishedVulnerability first disclosed.
2. 19-10-2026
   Last modifiedVulnerability information updated.

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.

• CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.