Multiple directory traversal vulnerabilities in Plex Media Server before 0.9.9.3 allow remote attackers to read arbitrary files via a .. (dot dot) in the URI to (1) manage/ or (2) web/ or remote authenticated users to read arbitrary files via a .. (dot dot) in the URI to resources/.
https://forums.plex.tv/index.php/topic/62832-plex-media-server/?p=583250