Uncontrolled Memory Allocation in FFmpeg by the FFmpeg Vendor
CVE-2026-125226

6.8MEDIUM

Key Information:

Vendor

Ffmpeg

Status
Ffmpeg
Vendor
CVE Published:
9 November 2026

What is CVE-2026-125226?

FFmpeg, up to version 9.0.2, contains an uncontrolled memory allocation vulnerability in the sbg_read_header() function located in libavformat/sbgdec.c. This vulnerability arises from an unbounded default frame size being derived from the sample rate specified in a SBaGen script. Attackers can exploit this by supplying a crafted script that declares an excessively high sample rate, leading the wavesynth decoder to allocate excessively large audio frames. This can exhaust memory resources, potentially resulting in a denial of service.

Affected Version(s)

FFmpeg 0 <= 9.0.2

References

https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25703
issue-tracking
https://github.com/FFmpeg/FFmpeg/commit/1f4b2e22cfba19f94...
patch
https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavformat/...
technical-description

CVSS V4

Score:
6.8
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Joshua Rogers (AISLE Research)
Michael Niedermayer
.