Mopidy before 4.0.5 Path Traversal via File Backend library.lookup

Mopidy before 4.0.5 contains a path traversal vulnerability that allows unauthenticated clients to access local files outside file/media_dirs because FileLibraryProvider.lookup() lacks a containment check. Attackers can call core.library.lookup or core.tracklist.add over JSON-RPC or WebSocket with file:// URIs to probe file existence, read tag metadata, and play out-of-sandbox files.