Denial of Service Vulnerability in FFmpeg JPEG Processing
CVE-2026-125246

5.7MEDIUM

Key Information:

Vendor

Ffmpeg

Status
Ffmpeg
Vendor
CVE Published:
9 November 2026

What is CVE-2026-125246?

FFmpeg, up to version 9.0.2, contains a vulnerability in the function cbs_jpeg_assemble_fragment() that may allow attackers to exploit improperly counted 0xff stuffing bytes in JPEG scan headers. By providing a maliciously crafted JPEG or MJPEG stream, an attacker can trigger an assertion failure (av_assert0 abort) during the processing of CBS-based bitstream filters, leading to potential denial of service conditions.

Affected Version(s)

FFmpeg 0 <= 9.0.2

References

https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25232
issue-tracking
https://github.com/FFmpeg/FFmpeg/commit/ee457fdcdb3a069ef...
patch
https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/c...
technical-description

CVSS V4

Score:
5.7
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Local
Attack Complexity:
High
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Joshua Rogers (AISLE Research)
Michael Niedermayer
.