Vulnerability · Published Aug 6, 2026 · Assigned by VulnCheck

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

High 7.8

In plain English

A high-severity out-of-bounds write in FFmpeg from FFmpeg. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.8High

Exploit odds (30 days)0.2%top 86.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	ffmpeg	no fix listed	DEBIAN-CVE-2026-70632
Debian:13	ffmpeg	no fix listed	DEBIAN-CVE-2026-70632
Debian:14	ffmpeg	7:9.0.2-1	DEBIAN-CVE-2026-70632
Ubuntu:26.10	ffmpeg	no fix listed	UBUNTU-CVE-2026-70632

Affected products (as reported)

Vendor	Product	Versions
FFmpeg	FFmpeg	4.4 – before 9.0

Weakness: CWE-787 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References

Pull Request issue-tracking
Introducing Commit related
Patch Commit patch
FFmpeg 9.0 Backport Commit patch
https://www.vulncheck.com/advisories/ffmpeg-heap-out-of-bounds-write-in-cfhd-decoder-via-avi-demuxing third-party-advisory