Out-of-Bounds Write Vulnerability in FFmpeg's VVC Decoder
CVE-2026-125244

8.5HIGH

Key Information:

Vendor

Ffmpeg

Status
Ffmpeg
Vendor
CVE Published:
9 November 2026

What is CVE-2026-125244?

An out-of-bounds write vulnerability exists in FFmpeg's VVC decoder within the sh_entry_points() function. This flaw can be exploited by attackers who provide a specially crafted VVC (H.266) bitstream, manipulating the SPS/PPS tile and WPP layout to generate an excessive number of entry points. This results in an overflow of entry_point_start_ctu, potentially leading to memory corruption within the decoder.

Affected Version(s)

FFmpeg 7.0 < 8.1.3

FFmpeg 9.0 < 9.0.2

References

https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24537
issue-tracking
https://github.com/FFmpeg/FFmpeg/commit/a809a784ec9ff9910...
patch
https://github.com/FFmpeg/FFmpeg/blob/n9.0.1/libavcodec/v...
technical-description

CVSS V4

Score:
8.5
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Umar Pathan (Umar0x)
Joshua Rogers (AISLE Research)
Umar Pathan
.