{"id":"CVE-2026-121941","aliases":["EUVD-2026-116898","GHSA-qw3h-2hqv-29vq"],"status":"published","title":"libmt32emu before 2.8.4 Heap Buffer Overflow via MidiStreamParserImpl::parseSysex","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.","severity":{"version":"4.0","score":8.5,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.0026,"percentile":0.17924,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-122"],"published":"2026-11-04T12:31:19Z","modified":"2026-11-05T13:11:14Z","products":[{"vendor":"munt","product":"libmt32emu"}],"references":[{"url":"https://github.com/munt/munt/issues/149","tags":["issue-tracking","report"]},{"url":"https://hackmd.io/@haindpwn/munt-midistreamparser-oversized-sysex-heap-overflow","tags":["third-party-advisory","advisory"]},{"url":"https://github.com/munt/munt/commit/1749f7fed5cdb3a9015acce076a1512b1615dc3b","tags":["patch","fix"]},{"url":"https://github.com/munt/munt/blob/libmt32emu_2_8_3/mt32emu/src/MidiStreamParser.cpp#L223-L257","tags":["technical-description","article"]},{"url":"https://www.vulncheck.com/advisories/libmt32emu-before-2.8.4-heap-buffer-overflow-via-midistreamparserimpl-parsesysex","tags":["third-party-advisory","advisory"]},{"url":"https://hackmd.io/@haindpwn/cve-2026-121941-munt-midistreamparser-oversized-sysex-heap-overflow","tags":["exploit","evidence"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121941","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-qw3h-2hqv-29vq"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/121xxx/CVE-2026-121941.json","tags":["advisory"]},{"url":"https://github.com/munt/munt","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-121941","title":"libmt32emu before 2.8.4 Heap Buffer Overflow via MidiStreamParserImpl::parseSysex","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.","status":"published","published":"2026-11-04T12:31:19.851Z","modified":"2026-11-04T20:18:07.407Z","cvss":[{"version":"4.0","score":8.5,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna"},{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-122"],"updated_at":"2026-11-04T21:42:22.271694Z"}],"euvd":[{"id":"EUVD-2026-116898","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.","status":"published","published":"2026-11-04T12:31:19Z","modified":"2026-11-04T20:18:07Z","cvss":[{"version":"4.0","score":8.5,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-04T21:45:44.368355Z"}],"ghsa":[{"id":"GHSA-qw3h-2hqv-29vq","title":"libmt32emu before 2.8.4 contains a heap buffer overflow vulnerability in MidiStreamParserImpl:...","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.","status":"published","published":"2026-11-04T15:32:30Z","modified":"2026-11-04T21:32:27Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"},{"version":"4.0","score":8.5,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"}],"cwes":["CWE-122"],"updated_at":"2026-11-04T21:42:45.289646Z"}],"nvd":[{"id":"CVE-2026-121941","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.","status":"published","published":"2026-11-04T13:17:28.56Z","modified":"2026-11-04T21:18:06.527Z","cvss":[{"version":"4.0","score":8.5,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-122"],"updated_at":"2026-11-04T23:43:43.486581Z"}],"osv":[{"id":"CVE-2026-121941","title":"libmt32emu before 2.8.4 Heap Buffer Overflow via MidiStreamParserImpl::parseSysex","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.","status":"published","published":"2026-11-04T12:31:19.851Z","modified":"2026-11-06T01:05:01.077395783Z","cvss":[{"version":"4.0","score":8.5,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-122"],"updated_at":"2026-11-06T01:32:47.895286Z"}]}}