Please upgrade here. These earlier versions are no longer being updated and have security issues.
HackerOne users: Testing against this community violates our program's Terms of Service and will result in your bounty being denied.
I don't have a self-hosted forum, but I do have one hosted on Vanilla.
Apparently something from the site in the title is sneaking its way into someone's posts, and I wonder if anyone else has had this problem. If so, how can you fix it?