CVE-2022-31152

Synapse is an open-source Matrix homeserver written and maintained by the
Matrix.org Foundation. The Matrix specification specifies a list of event
authorization
rules which
must be checked when determining if an event should be accepted into a
room. In versions of Synapse up to and including version 1.61.0, some of
these rules are not correctly applied. An attacker could craft events which
would be accepted by Synapse but not a spec-conformant server, potentially
causing divergence in the room state between servers. Administrators of
homeservers with federation enabled are advised to upgrade to version
1.62.0 or higher. Federation can be disabled by setting
federation_domain_whitelist
to an empty list ([]) as a workaround.