{"id":"CVE-2026-121941","title":"libmt32emu before 2.8.4 Heap Buffer Overflow via MidiStreamParserImpl::parseSysex","summary":"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 t…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-122"],"vendor":"munt","product":"libmt32emu","affected":["libmt32emu < 2.8.4"],"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"total","timestamp":"2026-11-04T20:17:29.860940Z"},"exploitAvailable":true,"published":"2026-11-04","updated":"2026-11-04","sourceUpdated":"2026-11-04T20:18:07.407Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-121941","references":[{"url":"https://github.com/munt/munt/issues/149"},{"url":"https://hackmd.io/@haindpwn/munt-midistreamparser-oversized-sysex-heap-overflow"},{"url":"https://github.com/munt/munt/commit/1749f7fed5cdb3a9015acce076a1512b1615dc3b"},{"url":"https://github.com/munt/munt/blob/libmt32emu_2_8_3/mt32emu/src/MidiStreamParser.cpp#L223-L257"},{"url":"https://www.vulncheck.com/advisories/libmt32emu-before-2.8.4-heap-buffer-overflow-via-midistreamparserimpl-parsesysex","label":"VulnCheck Advisory: libmt32emu before 2.8.4 Heap Buffer Overflow via MidiStreamParserImpl::parseSysex"}],"tags":["cve.org","exploit-available"],"ingestedAt":"2026-11-05T21:36:00.536Z","epss":0.0026,"epssPercentile":0.17836,"slug":"CVE-2026-121941","body":"## Overview\n\nlibmt32emu 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.\n\n## Affected\n\n- `libmt32emu < 2.8.4`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":55,"depthScoreParts":{"impact":42.9,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[]}