Vulnerability · Published Jul 24, 2026 · Assigned by VulnCheck

CVE-2026-66041FFmpeg 7.0 - 8.1.2 Heap Out-of-Bounds Write via vf_quirc Filter

High 8.8

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 0.5% (higher than 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)0.5%top 57.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

FFmpeg 7.0 through 8.1.2, fixed in commit 4da9812, contains a heap out-of-bounds write vulnerability in the vf_quirc filter that allows an attacker to corrupt heap memory by supplying a crafted PGS/SUP subtitle file with mismatched frame dimensions. Attackers can provide a subtitle file whose second presentation has larger dimensions than its first, causing av_image_copy_plane() to copy data exceeding the initial allocation size into the undersized libquirc grayscale image buffer, resulting in heap corruption and process crash with potential for code execution.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:13	ffmpeg	no fix listed	DEBIAN-CVE-2026-66041
Debian:14	ffmpeg	7:9.0.2-1	DEBIAN-CVE-2026-66041
Ubuntu:26.10	ffmpeg	no fix listed	UBUNTU-CVE-2026-66041

Affected products (as reported)

Vendor	Product	Versions
FFmpeg	FFmpeg	7.0 – through 8.1.2

Weakness: CWE-787 · 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-via-vf-quirc-filter third-party-advisory