---
id: CVE-2026-125096
title: FFmpeg through 9.0.2 Uninitialized Memory Disclosure via Tiertex SEQ Decoder
summary: >-
  FFmpeg through 9.0.2 contains an uninitialized memory disclosure vulnerability
  in libavcodec/tiertexseqv.c that allows attackers to leak stack contents by
  triggering failed RLE unpacking. Attackers can supply a crafted Tiertex SEQ
  file s…
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 <= 9.0.2
published: '2026-11-09'
updated: '2026-11-09'
sourceUpdated: '2026-11-09T19:10:52.889Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-125096'
references:
  - url: 'https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25715'
  - url: >-
      https://github.com/FFmpeg/FFmpeg/commit/c896bbb24535685509a816af09665cb73bf2d0c7
    label: Patch Commit
  - url: 'https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/tiertexseqv.c#L94'
  - url: 'https://github.com/FFmpeg/FFmpeg'
  - url: >-
      https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-uninitialized-memory-disclosure-via-tiertex-seq-decoder
    label: >-
      VulnCheck Advisory: FFmpeg through 9.0.2 Uninitialized Memory Disclosure
      via Tiertex SEQ Decoder
tags:
  - cve.org
ingestedAt: '2026-11-09T19:18:02.628Z'
---

## Overview

FFmpeg through 9.0.2 contains an uninitialized memory disclosure vulnerability in libavcodec/tiertexseqv.c that allows attackers to leak stack contents by triggering failed RLE unpacking. Attackers can supply a crafted Tiertex SEQ file so seq_decode_op1() copies an uninitialized 64-byte stack block into decoded frames, exposing stack memory in visible output.

## Affected

- `FFmpeg <= 9.0.2`

## Remediation

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