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CVE-2026-56209

HIGH 7.1

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

An arbitrary address write vulnerability was found in libaom, the reference AV1 codec implementation. A missing bounds check in the SVC (Scalable Video Coding) layer ID control function allows an attacker to inject an arbitrary pointer into the cyclic refresh map field via crafted image pixel values. The encoder then writes approximately 1,200 bytes at the attacker-controlled address. This is fully deterministic and does not require a separate information leak. An attacker who can supply frames to a network-facing libaom encoder with SVC enabled could exploit this for denial of service or potential code execution.

ELEVATED IMPACT

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

Exploitation likelihood

0.3%chance of exploitation in 30 days · 19th percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

7.1CVSS 3.1 · HIGH

  • ConfidentialityNone
  • IntegrityLow
  • 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: No special conditions — reliably repeatable

✓ 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:L/PR:N/UI:R/S:U/C:N/I:L/A:H

Sources: NVD · CVE.org · EPSS