libmodplug through 0.8.9.1 contains an out-of-bounds read in patsmplooped in src/loadpat.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 patloops, so an index of zero reads patloops[-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 ModPlugLoad entry point drives the path through CSoundFile::Create, CSoundFile::ReadMID, and MIDReadPatterns 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.