Citizen is a MediaWiki skin that makes extensions part of the cohesive experience. From versions 1.9.4 to before 3.4.0, page descriptions are inserted into raw HTML without proper sanitization by the Citizen skin when using the old search bar. Any user with page editing privileges can insert cross-site scripting (XSS) payloads into the DOM for other users who are searching for specific pages. This issue has been patched in version 3.4.0.

starcitizentools/citizen-skin is vulnerable to Stored XSS attack in the legacy search bar through page descriptions