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TI-2026-85052 Aliases CVE-2026-121941GHSA-qw3h-2hqv-29vq

Heap buffer overflow in libmt32emu SysEx parsing

Priority HIGH 72CWE-122Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-122 and the CVSS impact.

Summary

libmt32emu before 2.8.4 contains a heap-based buffer overflow (CWE-122) in MidiStreamParserImpl::parseSysex. Attackers can write past a heap allocation by supplying more than 32768 unterminated SysEx data bytes through the mt32emu_parse_stream API via MIDI files, ports, or sequencer clients. Successful exploitation can corrupt heap memory and crash the application.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.0026 17th percentileScored 2026-11-07
Fix Fixed libmt32emu (munt): 2.8.4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
muntlibmt32emubefore 2.8.42.8.4Patch availableCNA
  • libmt32emu Vendormunt Affected before 2.8.4 Fixed in 2.8.4 Patch available CNA

Remediation

Upgrade libmt32emu to version 2.8.4 or later, which fixes the flaw.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

  • Fix · CNA libmt32emu (munt) Fixed in 2.8.4

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-11-04 Threatist record created from CVE-2026-121941
  2. 2026-11-04 Alias added: GHSA-qw3h-2hqv-29vq
  3. 2026-11-04 CISA SSVC decision points changed
  4. 2026-11-04 Priority changed: MEDIUM → HIGH
  5. 2026-11-06 Affected versions changed · Red Hat
  6. 2026-11-06 CVSS score added · Red Hat

References

Patch 1

Advisory 1

Other 2

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences