In Jitsi Meet before 2.0.9779, the functionality to share an image using giphy was implemented in an insecure way, resulting in clients loading GIFs from any arbitrary URL if a message from another participant contains a URL encoded in the expected format.
In Jitsi Meet before 2.0.9779, the functionality to share a video file was implemented in an insecure way, resulting in clients loading videos from an arbitrary URL if a message from another participant contains a URL encoded in the expected format.