Libaom: libaom: remote code execution via svc layer context handling with attacker-controlled frames
Summary
| CVE | CVE-2026-56211 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-19 17:16:30 UTC |
| Updated | 2026-06-19 18:16:20 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 7.1 HIGH from [email protected]
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:H
Problem Types: CWE-787 | CWE-787 Out-of-bounds Write
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 7.1 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:H |
| 3.1 | CNA | CVSS | 7.1 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:H |
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Enterprise Linux 10 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 10 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux AI RHEL AI 3 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Hardened Images | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| aomedia.googlesource.com/aom/+/a93ba0ffaa | [email protected] | aomedia.googlesource.com | |
| issues.chromium.org/issues/503993985 | [email protected] | issues.chromium.org | |
| access.redhat.com/security/cve/CVE-2026-56211 | [email protected] | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Red Hat would like to thank The FuzzAnything Team (FuzzAnything) for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-06-19T00:00:00.000Z | Reported to Red Hat. |
| CNA | 2026-06-19T00:00:00.000Z | Made public. |
Workarounds
CNA: There is no complete mitigation for this vulnerability. The following measures can reduce risk: 1. If using libaom as a standalone encoder in a fork-based service, validate all SVC layer parameters (spatial_layer_id, temporal_layer_id) against configured bounds before passing them to the encoder API. 2. Avoid fork-based architectures for encoding services that accept untrusted input. Use thread-based or container-isolated workers instead, which prevent crash oracle attacks. 3. Restrict access to encoding services to trusted clients only. Do not expose SVC encoder configuration or frame submission to untrusted network input. 4. For Firefox and Thunderbird, ensure browsers are updated to versions that include the patched libaom (v3.14.0 or later). 5. Enable all available exploit mitigations (ASLR, PIE, stack canaries, CFI) on encoding service binaries.