the only FOSS-based service offering Matrix chat server hosting
2021-07-01 09:51 UTC (updated)
There is announcement about yesterday update on Matrix blog: https://matrix.org/blog/2021/06/30/security-update-synapse-1-37-1-released
Homeserver owners with open registration, review your users in synapse-admin, please
PS: I added RSS feed of matrix.org blog to this room, so you will see such updates as soon as they posted