CVE-2026-56208

Summary

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.

Affected Software

VendorProductVersion RangeStatus
Red HatRed Hat Hardened Images3.14.0-0.1.hum1 < *unaffected

Weaknesses

  • CWE-122: Heap-based Buffer Overflow

Workarounds

There is no complete mitigation for this vulnerability. The following measures can reduce risk:

  1. If using libaom as a standalone encoder library, avoid setting g_lag_in_frames to values >= 1 when processing untrusted input, or validate all encoder configuration parameters before passing them to the libaom API.
  2. For Firefox and Thunderbird, ensure browsers are updated to versions that include the patched libaom (v3.14.0 or later).
  3. For standalone libaom deployments (RHEL-AI, Hummingbird), restrict access to the encoding service to trusted clients only.
  4. Apply network-level access controls to limit who can submit video for encoding.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

libaom: libaom: heap buffer overflow in AV1 encoder first-pass stats buffer via LAP mode

Additional References

References