Microsoft APM is an open-source, community-driven dependency manager for AI agents. Prior to 0.8.12, Microsoft APM normalizes marketplace plugins by copying plugin components referenced in plugin.json into .apm/. The manifest fields agents, skills, commands, and hooks are attacker-controlled, but the implementation does not enforce that those paths remain inside the plugin directory. A malicious plugin can therefore use absolute paths or ../ traversal paths to copy arbitrary readable host files or directories from the installer's machine during apm install. This vulnerability is fixed in 0.8.12.