CVE-2026-75904 libmodplug <= 0.8.9.1 - Out-of-Bounds Read in pat_smplooped via Crafted MIDI File
An out-of-bounds read in libmodplug allows attackers to cause denial of service or disclose memory contents via a crafted MIDI file.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-75904?
CVE-2026-75904 is a medium-severity memory corruption vulnerability in Konstanty Bialkowski libmodplug, published on 18 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
libmodplug through 0.8.9.1 contains an out-of-bounds read in pat_smplooped in src/load_pat.cpp. The function validates only the upper bound of its sample index against MAXSMP and then subtracts one before indexing the 191-byte static array pat_loops, so an index of zero reads pat_loops[-1], one byte before the array. The index is the smpno field of a parsed MIDI event, which is initialised to zero and only later overwritten from a program-change parameter, so an event reaching the note test before an instrument is assigned carries zero. A 32-byte MIDI file supplied to the library's public ModPlug_Load entry point drives the path through CSoundFile::Create, CSoundFile::ReadMID, and MID_ReadPatterns to the read. The byte read out of bounds determines whether a note event is treated as looping, so adjacent static storage influences playback state.
Weakness: CWE-125
Which versions are affected by CVE-2026-75904?
How do I fix CVE-2026-75904?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-75904 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-75904 exists.
Sources
Also known as AZL-96854, DEBIAN-CVE-2026-75904, ECHO-64f1-9158-8f37, GHSA-prc8-cg98-hxwc, OESA-2026-3602, OESA-2026-3603 and 4 more.