CVE-2026-70632 HIGH

CVE-2026-70632: FFmpeg 4.4 < 9.0 Heap Out-of-Bounds Write in CFHD Decoder via AVI Demuxing

Vendor Ffmpeg
Product FFmpeg
Weakness CWE-787
Published August 6, 2026
Last update August 6, 2026

CVSS base score

8.5/10
Attack vector Local
Attack complexity Low
Privileges required None
User interaction
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

FFmpeg versions from 4.4 up to, but not including, 9.0 contain an out-of-bounds heap write vulnerability in the native GoPro CineForm HD (CFHD) decoder that allows remote attackers to corrupt heap memory by supplying a crafted AVI file during stream probing. The cfhd_decode() function fails to enforce the non-Bayer logical output-width invariant in the transform-type-2 reconstruction path, causing horiz_filter_clip() to write oversized 16-bit sample rows far beyond the allocated output frame buffer, which can be escalated to arbitrary code execution via overwrite of a live cleanup callback pointer.

Key dates

02Disclosure timeline

August 6, 2026 CVE published
August 6, 2026 Record updated