CVE-2025-9951 Remote code execution via Heap Buffer Overflow in FFmpeg JPEG2000
Attackers can achieve remote code execution or cause denial of service via a heap buffer overflow in FFmpeg's JPEG2000 decoder.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-9951?
CVE-2025-9951 is a high-severity memory corruption vulnerability in FFmpeg, published on 9 Sep 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A heap-buffer-overflow write exists in jpeg2000dec FFmpeg which allows an attacker to potentially gain remote code execution or cause denial of service via the channel definition cdef atom of JPEG2000.
Weakness: CWE-122
Which versions are affected by CVE-2025-9951?
How do I fix CVE-2025-9951?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-9951 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-9951 exists.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as DEBIAN-CVE-2025-9951, GHSA-39q3-f8jq-v6mg, JLSEC-2026-648, UBUNTU-CVE-2025-9951.