---
id: CVE-2026-125261
title: FFmpeg through 9.0.2 SGI Encoder Out-of-Bounds Read via sgienc.c
summary: >-
  FFmpeg through 9.0.2 contains an out-of-bounds read vulnerability in the SGI
  encoder's encode_frame() in libavcodec/sgienc.c, where unsigned size variables
  mis-handle negative linesize frames. Attackers can supply a video whose
  display m…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-125
vendor: FFmpeg
product: FFmpeg
affected:
  - FFmpeg <= 9.0.2
published: '2026-11-09'
updated: '2026-11-09'
sourceUpdated: '2026-11-09T19:12:03.938Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-125261'
references:
  - url: 'https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25690'
  - url: >-
      https://github.com/FFmpeg/FFmpeg/commit/c6e5b6105aa13f6b0df2a646da608078cfe52d79
    label: Patch Commit
  - url: 'https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/sgienc.c#L208'
  - url: 'https://github.com/FFmpeg/FFmpeg'
  - url: >-
      https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-sgi-encoder-out-of-bounds-read-via-sgienc-c
    label: >-
      VulnCheck Advisory: FFmpeg through 9.0.2 SGI Encoder Out-of-Bounds Read
      via sgienc.c
tags:
  - cve.org
ingestedAt: '2026-11-09T20:27:27.080Z'
---

## Overview

FFmpeg through 9.0.2 contains an out-of-bounds read vulnerability in the SGI encoder's encode_frame() in libavcodec/sgienc.c, where unsigned size variables mis-handle negative linesize frames. Attackers can supply a video whose display matrix triggers autorotate vflip, so transcoding to SGI images reads pixel data far outside the frame and crashes the process.

## Affected

- `FFmpeg <= 9.0.2`

## Remediation

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