Vulnerability · Published Jul 24, 2026 · Assigned by VulnCheck

CVE-2026-66036FFmpeg Heap Out-of-Bounds Write in vf_hqdn3d Filter

High 8.8

In plain English

A high-severity heap buffer overflow 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 0.4% (higher than 35% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)0.4%top 65.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

FFmpeg through 8.1.2, fixed in commit 5d7112c, contains a heap out-of-bounds write vulnerability in the vf_hqdn3d filter that allows attackers to corrupt heap memory by supplying a crafted video whose frame resolution increases between frames when filtergraph reinitialization is disabled via the -reinit_filter 0 option. Attackers can provide a malicious video input where vf_hqdn3d.config_input() allocates undersized per-plane line-history buffers based on the initial frame width, and subsequent larger frames cause denoise_spatial() to write beyond the allocation boundary, resulting in heap memory corruption.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	ffmpeg	no fix listed	DEBIAN-CVE-2026-66036
Debian:13	ffmpeg	no fix listed	DEBIAN-CVE-2026-66036
Debian:14	ffmpeg	7:9.0.2-1	DEBIAN-CVE-2026-66036
Ubuntu:26.10	ffmpeg	no fix listed	UBUNTU-CVE-2026-66036

Affected products (as reported)

Vendor	Product	Versions
FFmpeg	FFmpeg	0 – through 8.1.2

Weakness: CWE-122 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References

Pull Request issue-tracking
Patch Commit patch
https://www.vulncheck.com/advisories/ffmpeg-heap-out-of-bounds-write-in-vf-hqdn3d-filter third-party-advisory