CVE-2026-56209 Libaom: libaom: arbitrary address write via svc layer context oob and cyclic refresh map pointer hijack
Attackers can achieve arbitrary code execution or denial of service by exploiting a missing bounds check in the libaom AV1 encoder when SVC is enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-56209?
CVE-2026-56209 is a high-severity memory corruption vulnerability in Red Hat AI Inference Server, published on 19 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-787
Which versions are affected by CVE-2026-56209?
How do I fix CVE-2026-56209?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-56209 being exploited?
There is no known exploitation of CVE-2026-56209 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-56209, ECHO-2e12-e6da-9a4b, GHSA-8vmr-q5h8-3vc5, ROOT-OS-DEBIAN-11-CVE-2026-56209, UBUNTU-CVE-2026-56209.