SUSE-IT together with the openSUSE Heroes routinely performs service to Services on an ongoing basis to ensure that everything is up to date and running smoothly.
During one of these service routines, the Matrix service behind matrix.opensuse.org (and https://chat.opensuse.org/ ) was identified as running an old, unmaintained and vulnerable version. While there is currently no incident of any (successful) attacks, the team decided to take the service down until an update is deployed.