---
id: CVE-2026-125226
title: FFmpeg through 9.0.2 Excessive Memory Allocation via SBaGen Demuxer
summary: >-
  FFmpeg through 9.0.2 contains an uncontrolled memory allocation vulnerability
  in sbg_read_header() in libavformat/sbgdec.c that derives an unbounded default
  frame size from the script's sample rate. Attackers can supply a crafted
  SBaGen …
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-789
vendor: FFmpeg
product: FFmpeg
affected:
  - FFmpeg <= 9.0.2
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-09T20:58:28.536933Z'
published: '2026-11-09'
updated: '2026-11-09'
sourceUpdated: '2026-11-09T21:06:54.770Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-125226'
references:
  - url: 'https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25703'
  - url: >-
      https://github.com/FFmpeg/FFmpeg/commit/1f4b2e22cfba19f94489ec4a17130f4f0d5d8a0c
    label: Patch Commit
  - url: 'https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavformat/sbgdec.c#L1419'
  - url: 'https://github.com/FFmpeg/FFmpeg'
  - url: >-
      https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-excessive-memory-allocation-via-sbagen-demuxer
    label: >-
      VulnCheck Advisory: FFmpeg through 9.0.2 Excessive Memory Allocation via
      SBaGen Demuxer
tags:
  - cve.org
ingestedAt: '2026-11-09T19:18:02.589Z'
---

## Overview

FFmpeg through 9.0.2 contains an uncontrolled memory allocation vulnerability in sbg_read_header() in libavformat/sbgdec.c that derives an unbounded default frame size from the script's sample rate. Attackers can supply a crafted SBaGen script declaring a very high -r sample rate so the wavesynth decoder allocates enormous audio frames, exhausting memory and causing denial of service.

## Affected

- `FFmpeg <= 9.0.2`

## Remediation

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