WildMIDI through 0.5.0 contains a heap out-of-bounds read vulnerability in the HMP parser _WM_ParseNewHmp() that allows attackers to read beyond buffers via underflowed chunk lengths. Attackers can supply a crafted .hmp file with a chunk length of 0-12 that wraps to roughly 4 GB, crashing applications or exposing heap bytes through WildMidi_GetInfo().