The vulnerability seems to have been patched, federation is re-enabled and so is community creation.
Thank you for your patience yall. It seems our mitigation efforts worked and we were likely never in danger. If you are concerned about other accounts on affected instances, it is unlikely your personal data was breached. Keep a look out for more info on those instances though as they will likely explain things more.
@gavi@lemmynsfw.com My Account in this instance gets constantly logged out again from Memmy and Mlem. So I suppose that is an lemmynsfw issue, because my other account at another instance just works fine with both apps.