---
id: CVE-2026-125171
title: FFmpeg through 9.0.2 Out-of-Bounds Read in Musepack SV7 Decoder via mpc7.c
summary: >-
  FFmpeg through 9.0.2 contains an out-of-bounds read vulnerability in the
  Musepack SV7 decoder because mpc7_decode_init() does not validate lastframelen
  against MPC_FRAME_SIZE. Attackers can supply a crafted Musepack SV7 file
  declaring an…
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: '2026-11-09T19:10:59.844Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-125171'
references:
  - url: 'https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25074'
  - url: >-
      https://github.com/FFmpeg/FFmpeg/commit/5d59b7c45d7142bddd13ddc8891e72c5c7dc991b
    label: Patch Commit
  - url: 'https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/mpc7.c#L281'
  - url: 'https://github.com/FFmpeg/FFmpeg'
  - url: >-
      https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-out-of-bounds-read-in-musepack-sv7-decoder-via-mpc7-c
    label: >-
      VulnCheck Advisory: FFmpeg through 9.0.2 Out-of-Bounds Read in Musepack
      SV7 Decoder via mpc7.c
tags:
  - cve.org
ingestedAt: '2026-11-09T19:18:02.621Z'
---

## Overview

FFmpeg through 9.0.2 contains an out-of-bounds read vulnerability in the Musepack SV7 decoder because mpc7_decode_init() does not validate lastframelen against MPC_FRAME_SIZE. Attackers can supply a crafted Musepack SV7 file declaring an oversized final frame, causing consumers of decoded frames to read past the audio buffer, leading to crashes or heap memory disclosure.

## Affected

- `FFmpeg <= 9.0.2`

## Remediation

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