CVE-2026-121941 libmt32emu before 2.8.4 Heap Buffer Overflow via MidiStreamParserImpl::parseSysex

High 8.5 Published 4 Nov 2026 Updated 4 Nov 2026

Exploited in the wild: Not known
Fix: None listed

What is CVE-2026-121941?

CVE-2026-121941 is a high-severity vulnerability in munt libmt32emu, published on 4 Nov 2026.

Official 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.

Weakness: CWE-122

Which versions are affected by CVE-2026-121941?

How do I fix CVE-2026-121941?

No fix has been published for CVE-2026-121941 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-121941 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-121941 exists.

Sources

Also known as GHSA-qw3h-2hqv-29vq.