FFmpeg through 9.0.2 SGI Encoder Out-of-Bounds Read via sgienc.c

Advisories

FFmpeg through 9.0.2 SGI Encoder Out-of-Bounds Read via sgienc.c

Severity: medium
Date: 11/9/2026
Affecting: FFmpeg <= 9.0.2
CVE: CVE-2026-125261
CWE: CWE-125 Out-of-bounds Read
CVSS: 6.9
CVSS V4 Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
References: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25690
Patch Commit
https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/sgienc.c#L208
https://github.com/FFmpeg/FFmpeg
Credit: Joshua Rogers (AISLE Research), Michael Niedermayer
Description: 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.

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