cross-posted from: https://sh.itjust.works/post/923025
lemmy.world is a victim of an XSS attack right now and the hacker simply injected a JavaScript redirection into the sidebar.
It appears the Lemmy backend does not escape HTML in the main sidebar. Not sure if this is also true for community sidebars.
Pretend that all HTML needs to be escaped and only disable it on a case-by-case basis.
And use the Content-Security-Policy header to limit where scripts can load from, just in case you miss escaping HTML somewhere.
They did, but then they turned those protections off, lol