The FV Flowplayer Video Player plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'fv_player_videos[_fv_player_user_video][]' parameter in all versions up to, and including, 7.5.55.7212 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires an administrator to have enabled the "Allow visitors to upload videos to their profile" (profile_videos_enable_bio) setting before Subscriber-level users can submit profile videos.