CVE-2026-34247

WWBN AVideo is an open source video platform. In versions up to and including 26.0, the `plugin/Live/uploadPoster.php` endpoint allows any authenticated user to overwrite the poster image for any scheduled live stream by supplying an arbitrary `live_schedule_id`. The endpoint only checks `User::isLogged()` but never verifies that the authenticated user owns the targeted schedule. After overwriting the poster, the endpoint broadcasts a `socketLiveOFFCallback` notification containing the victim's broadcast key and user ID to all connected WebSocket clients. Commit 5fcb3bdf59f26d65e203cfbc8a685356ba300b60 fixes the issue.