---
id: CVE-2026-125208
title: FFmpeg through 9.0.2 V4L2 M2M Encoder Out-of-Bounds Write in v4l2_buffers.c
summary: >-
  FFmpeg through 9.0.2 contains an out-of-bounds write vulnerability in
  v4l2_buffer_swframe_to_buf() in libavcodec/v4l2_buffers.c because cumulative
  plane offsets are not checked against the V4L2 buffer length. Attackers can
  supply crafted…
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-787
vendor: FFmpeg
product: FFmpeg
affected:
  - FFmpeg <= 9.0.2
published: '2026-11-09'
updated: '2026-11-09'
sourceUpdated: '2026-11-09T19:11:25.840Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-125208'
references:
  - url: 'https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24328'
  - url: >-
      https://github.com/FFmpeg/FFmpeg/commit/b8f159858e2fd29dae4fa34d9e713bbf9bbf190e
    label: Patch Commit
  - url: >-
      https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/v4l2_buffers.c#L309
  - url: 'https://github.com/FFmpeg/FFmpeg'
  - url: >-
      https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-v4l2-m2m-encoder-out-of-bounds-write-in-v4l2-buffers-c
    label: >-
      VulnCheck Advisory: FFmpeg through 9.0.2 V4L2 M2M Encoder Out-of-Bounds
      Write in v4l2_buffers.c
tags:
  - cve.org
ingestedAt: '2026-11-09T19:18:02.596Z'
---

## Overview

FFmpeg through 9.0.2 contains an out-of-bounds write vulnerability in v4l2_buffer_swframe_to_buf() in libavcodec/v4l2_buffers.c because cumulative plane offsets are not checked against the V4L2 buffer length. Attackers can supply crafted video whose dimensions or padding cause unsigned wraparound in v4l2_bufref_to_buf(), making memcpy() write past the mmaped driver buffer during V4L2 M2M encoding.

## Affected

- `FFmpeg <= 9.0.2`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.