CVE-2026-90783

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

HIGH
7.8
CVSS Score
Published: September 13, 2026 at 12:22 PM UTC
Updated: September 30, 2026 at 08:17 PM UTC
1 product affected across 1 vendorMKVToolNix

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Severity
HIGH7.8
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 101.0
Vendor states this is fixed in 1495126138e086080f0163bee27fafbdf956a1d0 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.8HIGHVulnCheck
Attack Vector
LOCAL
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-680

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