CVE-2026-70632 FFmpeg 4.4 < 9.0 Heap Out-of-Bounds Write in CFHD Decoder via AVI Demuxing
Remote attackers can achieve arbitrary code execution by supplying a crafted AVI file to FFmpeg, exploiting a heap out-of-bounds write in the CFHD decoder.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-70632?
CVE-2026-70632 is a high-severity memory corruption vulnerability in Ffmpeg Ffmpeg, published on 6 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
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.
Weakness: CWE-787
Which versions are affected by CVE-2026-70632?
It affects 1 product.
Products include Ffmpeg Ffmpeg.
How do I fix CVE-2026-70632?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-70632 being exploited?
There is no known exploitation of CVE-2026-70632 in the wild and no public exploit code.
Other vulnerabilities in Ffmpeg Ffmpeg
Sources
Also known as DEBIAN-CVE-2026-70632, ECHO-d1bb-4d4f-3ea6, GHSA-q24x-99v6-6hxc, JLSEC-2026-1192, UBUNTU-CVE-2026-70632.