---
id: CVE-2026-125266
title: FFmpeg through 9.0.2 Uninitialized Stack Memory Disclosure via SANM Codec 23
summary: >-
  FFmpeg through 9.0.2 contains an uninitialized stack memory disclosure
  vulnerability in old_codec23() of libavcodec/sanm.c that leaks stack bytes
  into decoded frames. Attackers can supply a crafted LucasArts SMUSH/SANM
  animation using co…
severity: low
cvss: 3.3
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N'
cvssSource: cna
cwe:
  - CWE-908
vendor: FFmpeg
product: FFmpeg
affected:
  - FFmpeg >= 8.0 <= 9.0.2
published: '2026-11-09'
updated: '2026-11-09'
sourceUpdated: '2026-11-09T19:12:07.485Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-125266'
references:
  - url: 'https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25718'
  - url: >-
      https://github.com/FFmpeg/FFmpeg/commit/d42cb1925987cc27899441ce39fa7bd2647dc72e
    label: Patch Commit
  - url: 'https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/sanm.c#L799'
  - url: 'https://github.com/FFmpeg/FFmpeg'
  - url: >-
      https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-uninitialized-stack-memory-disclosure-via-sanm-codec-23
    label: >-
      VulnCheck Advisory: FFmpeg through 9.0.2 Uninitialized Stack Memory
      Disclosure via SANM Codec 23
tags:
  - cve.org
ingestedAt: '2026-11-09T20:27:27.074Z'
---

## Overview

FFmpeg through 9.0.2 contains an uninitialized stack memory disclosure vulnerability in old_codec23() of libavcodec/sanm.c that leaks stack bytes into decoded frames. Attackers can supply a crafted LucasArts SMUSH/SANM animation using codec 23 with an inline table to expose decoder process stack memory in output video.

## Affected

- `FFmpeg >= 8.0 <= 9.0.2`

## Remediation

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