MediaWiki is vulnerable to information disclosure. pecial:UserRights exposes the existence of hidden users to remote attackers.
lists.fedoraproject.org/archives/list/[email protected]/message/RTTPZ7XMDS66I442OLLHXBDNP2LCBJU6/
lists.wikimedia.org/pipermail/mediawiki-l/2020-September/048480.html
lists.wikimedia.org/pipermail/mediawiki-l/2020-September/048488.html
meta.wikimedia.org/wiki/Special:UserRights
security-tracker.debian.org/tracker/CVE-2020-25813