A buffer overflow vulnerability exists in Heroes of Might and Magic III Complete 4.0.0.0, HD Mod 3.808 build 9, and Demo 1.0.0.0 via malicious .h3m map files that exploit object sprite name parsing logic. The vulnerability occurs during in-game map loading when a crafted object name causes a buffer overflow, potentially allowing arbitrary code execution. Exploitation requires the victim to open a malicious map file within the game.