---
id: "CVE-2026-125242"
page: "https://infrastack.ai/live/CVE-2026-125242"
kind: "vulnerability"
aliases: ["CVE-2026-125242"]
title: "FFmpeg: crafted H.264 streams leak memory and exhaust heap"
severity: "medium"
cvss: 5.7
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["ffmpeg", "h264", "libavcodec", "runtime", "self-hosted", "vdpau"]
not_affected_if: ["trusted-input-only", "vdpau-not-used"]
published_at: "2026-11-09T19:17:02+00:00"
first_seen_at: "2026-11-09T19:28:20+00:00"
updated_at: "2026-11-09T19:31:59+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-125242", "first_seen_at": "2026-11-09T19:28:20+00:00"}]
exploit_sources: []
---

# FFmpeg: crafted H.264 streams leak memory and exhaust heap

Link for people: https://infrastack.ai/live/CVE-2026-125242 (this .md is for agents)

FFmpeg's VDPAU decoding code in libavcodec leaks a buffer table when a picture is aborted before end_frame. A crafted H.264 stream with malformed NAL units can repeatedly trigger this, exhausting heap memory and causing a denial of service.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed FFmpeg version with `ffmpeg -version` and compare it against the ranges in the NVD entry.
- Check whether FFmpeg is built with VDPAU support (`ffmpeg -hwaccels` lists vdpau when it is enabled).

## Timeline

- 2026-11-09T19:28:20+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-125242

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-memory-leak-via-vdpau-hwaccel-bitstream-buffer-table
- [fix] Patch: github.com https://github.com/FFmpeg/FFmpeg/commit/2c6cd8098844f2367f8ba0a3a483e405c8f76449
- [fix] Patch: github.com https://github.com/FFmpeg/FFmpeg/commit/eac2bedcf6245552b39eed32b334851bc6a1b8fa

## From the sources

FFmpeg through 9.0.2 contains a memory leak vulnerability in libavcodec/vdpau.c that allows attackers to exhaust heap memory by aborting pictures before end_frame. Attackers can supply crafted H.264 streams with malformed NAL units that repeatedly abandon pictures, leaking the bitstream_buffers table continuously and causing denial of service.

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_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_