Realms have been hacked!!

Recently I started using Realms, but on the night of July 4th, 2019 Japan time, people who have not been invited to realms have come and I'm trying to destroy.
When the person logged in, "[Player name] logged in via lan" appears in the chat log. You should not enter realms via lan because you are not the host. It is probably a bug or a vulnerability in realms itself.
Please deal with it