High · CVSS 8.5CVE-2026-121941

libmt32emu before 2.8.4 Heap Buffer Overflow via MidiStreamParserImpl::parseSysexCVE-2026-121941

Answer in brief

CVE-2026-121941 records a High severity (CVSS 8.5) vulnerability in libmt32emu before 2.8.4 Heap Buffer Overflow via MidiStreamParserImpl::parseSysex. The current sources do not mark it as known exploited. The current feed maps munt/libmt32emu (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 Nov 4, 2026Updated Nov 4, 2026Source checked Nov 4, 2026First seen by HOL Nov 4, 2026Material review Nov 4, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.5
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 8.5. 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 munt/libmt32emu (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
munt/libmt32emugeneric	>=0 <2.8.4	2.8.4

Recommended response

Check inventory. Check lockfiles and deployed manifests for munt/libmt32emu.
Review the reported fix. Update munt/libmt32emu to 2.8.4 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Nov 4, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Nov 4, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Nov 4, 2026

Sources and claim methodology

Upstream source description

libmt32emu before 2.8.4 contains a heap buffer overflow vulnerability in MidiStreamParserImpl::parseSysex that allows attackers to write past a heap allocation by supplying oversized unterminated SysEx messages. Attackers can feed more than 32768 SysEx data bytes through the mt32emu_parse_stream API via MIDI files, ports, or sequencer clients to corrupt heap memory and crash the application.

Quoted source text, attributed separately from HOL analysis.

Apache OpenOffice: Heap Buffer Overflow in DXF LWPOLYLINE import could cause memory corruptionAlso CWE-122