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CVE-2026-56209

HIGH 7.1

Published 2026-06-19 · Last modified 2026-07-21

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

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-56209/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-56209/poc.json

Affected

Vendors Red Hat

Products Red Hat Enterprise Linux Ai 3.5 For Rhel 9 Red Hat Hardened Images Red Hat Ai Inference Server Red Hat Enterprise Linux 10 Red Hat Enterprise Linux 9 Red Hat Openshift Ai (Rhoai) 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

All CVSS metrics

  • HIGH 7.1 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
  • HIGH 7.1 v3.1 · ADP Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
  • HIGH 7.1 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H

Sources: NVD · CVE.org · EPSS