CVE-2026-90783 MKVToolNix through 101.0 Heap Buffer Overflow via avilib ODML Superindex Integer Wraparound
Attackers can trigger a heap buffer overflow in MKVToolNix by crafting a malicious AVI file, potentially leading to code execution or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-90783?
CVE-2026-90783 is a high-severity vulnerability in Moritz Bunkus MKVToolNix, published on 13 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
MKVToolNix through 101.0 contains a heap buffer overflow in the bundled avilib library's ODML superindex parser due to integer wraparound in 32-bit arithmetic. Attackers can craft a malicious AVI file with oversized entry counts that cause an undersized heap allocation, allowing a heap buffer overflow when the file is parsed with mkvmerge.
Weakness: CWE-680
Which versions are affected by CVE-2026-90783?
Linux distribution packages (2)
mkvtoolnix openSUSE:Leap 16.0 | All versions | 95.0-bp160.2.1 |
mkvtoolnix openSUSE:Tumbleweed | All versions | 101.0-2.1 |
How do I fix CVE-2026-90783?
Apply the vendor's patch.
Is CVE-2026-90783 being exploited?
There is no known exploitation of CVE-2026-90783 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-90783, GHSA-x9xf-h66v-mjmc, UBUNTU-CVE-2026-90783, openSUSE-SU-2026:11779-1, openSUSE-SU-2026:21867-1.