CVE-2026-66041 FFmpeg 7.0 - 8.1.2 Heap Out-of-Bounds Write via vf_quirc Filter
Heap out-of-bounds write in FFmpeg's vf_quirc filter allows attackers to execute code or crash the application via crafted subtitle files.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-66041?
CVE-2026-66041 is a high-severity memory corruption vulnerability in Ffmpeg Ffmpeg, published on 24 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
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.
Weakness: CWE-787
Which versions are affected by CVE-2026-66041?
It affects 1 product.
Products include Ffmpeg Ffmpeg.
How do I fix CVE-2026-66041?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-66041 being exploited?
There is no known exploitation of CVE-2026-66041 in the wild and no public exploit code.
Other vulnerabilities in Ffmpeg Ffmpeg
Sources
Also known as DEBIAN-CVE-2026-66041, GHSA-frhp-m687-9g3q, JLSEC-2026-1187, MINI-rp5p-f8pw-rv8x, UBUNTU-CVE-2026-66041.