---
id: CVE-2026-125253
title: FFmpeg through 9.0.2 VP9 CBS Superframe Integer Overflow Out-of-Bounds Read
summary: >-
  FFmpeg through 9.0.2 contains an integer overflow in cbs_vp9_split_fragment()
  in libavcodec/cbs_vp9.c that wraps the superframe size check on 32-bit builds.
  Attackers can supply a crafted VP9 packet with a forged superframe index
  contain…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-190
vendor: FFmpeg
product: FFmpeg
affected:
  - FFmpeg <= 9.0.2
published: '2026-11-09'
updated: '2026-11-09'
sourceUpdated: '2026-11-09T19:11:58.269Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-125253'
references:
  - url: 'https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25232'
  - url: >-
      https://github.com/FFmpeg/FFmpeg/commit/6280907da48c4dd78f95ef5c713a29c7702153a3
    label: Patch Commit
  - url: 'https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/cbs_vp9.c#L400'
  - url: 'https://github.com/FFmpeg/FFmpeg'
  - url: >-
      https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-vp9-cbs-superframe-integer-overflow-out-of-bounds-read
    label: >-
      VulnCheck Advisory: FFmpeg through 9.0.2 VP9 CBS Superframe Integer
      Overflow Out-of-Bounds Read
tags:
  - cve.org
ingestedAt: '2026-11-09T20:27:27.090Z'
---

## Overview

FFmpeg through 9.0.2 contains an integer overflow in cbs_vp9_split_fragment() in libavcodec/cbs_vp9.c that wraps the superframe size check on 32-bit builds. Attackers can supply a crafted VP9 packet with a forged superframe index containing near-2^32 frame sizes, causing out-of-bounds reads that crash 32-bit applications.

## Affected

- `FFmpeg <= 9.0.2`

## Remediation

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