mediawiki is vulnerable to cross-site scripting. The vulnerability exists due to messages are output in HTML unescaped.
lists.fedoraproject.org/archives/list/[email protected]/message/26UJGHF7LJDOCQN6A3Z4PM7PYRKENJHE/
lists.fedoraproject.org/archives/list/[email protected]/message/2OMSV7B2TCFBOCICN3B4SMQP5HVRJQIT/
phabricator.wikimedia.org/T278014
security-tracker.debian.org/tracker/CVE-2021-30154
security.gentoo.org/glsa/202107-40
www.debian.org/security/2021/dsa-4889