CVE-2020-35474
In MediaWiki before 1.35.1, the combination of Html::rawElement and Message::text leads to XSS because the definition of MediaWiki:recentchanges-legend-watchlistexpiry can be changed onwiki so that the output is raw HTML.
Date published : 2020-12-18
https://lists.wikimedia.org/pipermail/mediawiki-announce/2020-December/000268.html