CVE-2026-90783: Moritz Bunkus Mkvtoolnix

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Moritz Bunkus Mkvtoolnix: up to and including 101.0

Published 2026-09-13. Last modified 2026-09-30.