CVE-2026-66041: Ffmpeg

High severity, CVSS 7.8. EPSS: 0.5% chance of exploitation in the next 30 days.

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 products

• Ffmpeg Ffmpeg: from 7.0, up to and including 8.1.2

Published 2026-07-24. Last modified 2026-08-07.