CVE-2026-121941
libmt32emu before 2.8.4 Heap Buffer Overflow via MidiStreamParserImpl::parseSysex
CVSS Score
7.8
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-122 |
| Vendor | munt |
| Product | libmt32emu |
| Published | Nov 4, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
munt / libmt32emu
0 < 2.8.4
References
github.com: https://github.com/munt/munt/issues/149 hackmd.io: https://hackmd.io/@haindpwn/munt-midistreamparser-oversized-sysex-heap-overflow github.com: https://github.com/munt/munt/commit/1749f7fed5cdb3a9015acce076a1512b1615dc3b github.com: https://github.com/munt/munt/blob/libmt32emu_2_8_3/mt32emu/src/MidiStreamParser.cpp#L223-L257 vulncheck.com: https://www.vulncheck.com/advisories/libmt32emu-before-2.8.4-heap-buffer-overflow-via-midistreamparserimpl-parsesysex
Credits
HaiND from the Post and Telecommunication Institute of Technology