CVE-2026-90783 PUBLISHED

MKVToolNix through 101.0 Heap Buffer Overflow via avilib ODML Superindex Integer Wraparound

Assigner: VulnCheck
Reserved: 13.09.2026 Published: 13.09.2026 Updated: 13.09.2026

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.

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS Score: 7.8

Attack Vector	Local	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	Required	Availability Impact	High

CVSS 3.1

CVSS Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.5

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Local	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

Product Status

Vendor	Moritz Bunkus
Product	MKVToolNix
Versions	Default: unaffected affected from 0 to 101.0 (incl.) Version 1495126138e086080f0163bee27fafbdf956a1d0 is unaffected

CVE-2026-90783 PUBLISHED

MKVToolNix through 101.0 Heap Buffer Overflow via avilib ODML Superindex Integer Wraparound

Metrics

Product Status

Credits

References

Problem Types