NVD security advisoryHigh
High advisory for libmt32emu
CVE-2026-121941 · Reported 4 Nov 2026
Full advisory details, affected packages, severity context, and original source.
Affected technology
libmt32emuAffected product
Advisory overview
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.
Related references
- https://github.com/munt/munt/blob/libmt32emu_2_8_3/mt32emu/src/MidiStreamParser.cpp#L223-L257
- https://github.com/munt/munt/commit/1749f7fed5cdb3a9015acce076a1512b1615dc3b
- https://github.com/munt/munt/issues/149
- https://hackmd.io/@haindpwn/munt-midistreamparser-oversized-sysex-heap-overflow
- https://www.vulncheck.com/advisories/libmt32emu-before-2.8.4-heap-buffer-overflow-via-midistreamparserimpl-parsesysex