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CVE-2026-56211

HIGH 7.1

Published 2026-06-19 · Last modified 2026-06-30

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.

ELEVATED IMPACT

Severe if exploited (CVSS 7.1), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.4%chance of exploitation in 30 days · 32nd percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

7.1CVSS 3.1 · HIGH

  • ConfidentialityLow
  • IntegrityHigh
  • AvailabilityHigh

What an attacker needs

  • Access: Reachable over the network — no local access needed
  • Privileges: No account or privileges required
  • User interaction: A user must take an action (click / open a file)
  • Complexity: Needs a race window or specific setup

✓ lowers the bar for an attacker · ⚠ raises it

Affected

Vendors Red Hat

Products Red Hat Hardened Images Red Hat Enterprise Linux 10 Red Hat Enterprise Linux 9 Red Hat Enterprise Linux Ai (Rhel Ai) 3

Weakness (CWE)

  • CWE-787: Out-of-bounds write

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:H

Sources: NVD · CVE.org · EPSS