1 files changed, 7 insertions, 0 deletions
diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index 9b99f0f9d7..5263f09aaa 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -309,6 +309,13 @@ class RoomMemberHandler(object):
                 )
 
         if effective_membership_state == Membership.INVITE:
+            # block any attempts to invite the server notices mxid
+            if target.to_string() == self._server_notices_mxid:
+                raise SynapseError(
+                    http_client.FORBIDDEN,
+                    "Cannot invite this user",
+                )
+
             block_invite = False
 
             if (self._server_notices_mxid is not None and