This message for everyone on the fediverse:

First, please ensure you go into your account settings and enable two/multi factor authentication. No, I mean do it right now. I’ll wait till you’re done.

…

…

Ok, thank you.

Now, if you are the admin of a mastodon instance, please go upgrade to 4.0.2 ASAP.

Background: https://portswigger.net/research/stealing-passwords-from-infosec-mastodon-without-bypassing-csp