---
id: CVE-2026-125231
title: FFmpeg 4.4 through 9.0.2 NULL Pointer Dereference via adx_decode_header()
summary: >-
  FFmpeg 4.4 through 9.0.2 contains a NULL pointer dereference vulnerability in
  libavcodec/adxdec.c because adx_decode_header() updates the channel layout
  before validating the sample rate. Attackers can supply a crafted ADX/AAX
  stream wit…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-476
vendor: FFmpeg
product: FFmpeg
affected:
  - FFmpeg >= 4.4 <= 9.0.2
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-09T20:57:57.261031Z'
published: '2026-11-09'
updated: '2026-11-09'
sourceUpdated: '2026-11-09T21:06:54.339Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-125231'
references:
  - url: 'https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25703'
  - url: >-
      https://github.com/FFmpeg/FFmpeg/commit/515dcad73d77711507083cae3913c9327c0977c6
    label: Patch Commit
  - url: 'https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/adxdec.c#L77'
  - url: 'https://github.com/FFmpeg/FFmpeg'
  - url: >-
      https://www.vulncheck.com/advisories/ffmpeg-4.4-through-9.0.2-null-pointer-dereference-via-adx-decode-header
    label: >-
      VulnCheck Advisory: FFmpeg 4.4 through 9.0.2 NULL Pointer Dereference via
      adx_decode_header()
tags:
  - cve.org
ingestedAt: '2026-11-09T19:18:02.585Z'
---

## Overview

FFmpeg 4.4 through 9.0.2 contains a NULL pointer dereference vulnerability in libavcodec/adxdec.c because adx_decode_header() updates the channel layout before validating the sample rate. Attackers can supply a crafted ADX/AAX stream with mid-stream new-extradata side data carrying an invalid sample rate, causing adx_decode() to write through NULL plane pointers and crash the application.

## Affected

- `FFmpeg >= 4.4 <= 9.0.2`

## Remediation

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