MKVToolNix through 101.0 Heap Buffer Overflow via avilib ODML Superindex Integer Wraparound (CVE-2026-90783) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-90783

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

Answer in brief

CVE-2026-90783 records a Unknown severity vulnerability in MKVToolNix through 101.0 Heap Buffer Overflow via avilib ODML Superindex Integer Wraparound. The current sources do not mark it as known exploited. The current feed maps Moritz Bunkus/MKVToolNix (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 13, 2026Updated Sep 13, 2026Source checked Sep 14, 2026First seen by HOL Sep 13, 2026Material review Sep 13, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Moritz Bunkus/MKVToolNix (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Moritz Bunkus/MKVToolNixgeneric	0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Moritz Bunkus/MKVToolNix.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 13, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 13, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 13, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.