Buffer overflow in Ffmpeg
CVE-2026-70632
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.
Vulnerability class: Buffer Overflow
EPSS: 0.002 (10.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
Affected products
- Ffmpeg — versions 4.4
Weakness classification (CWE)
References
- disclosure@vulncheck.com (related, Patch)
- disclosure@vulncheck.com (Patch, patch)
- disclosure@vulncheck.com (Patch, patch)
- disclosure@vulncheck.com (issue-tracking, Patch, Issue Tracking)
- disclosure@vulncheck.com (Patch, Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-70632?
- CVE-2026-70632 is a high-severity vulnerability in Ffmpeg, classified under Out-of-bounds Write. CVSS score: 7.8/10. Published 2026-08-06.
- How severe is CVE-2026-70632?
- High severity. CVSS v3 base score is 7.8 out of 10.