DataDump is a MediaWiki extension that provides dumps of wikis. Several interface messages are unescaped (more specifically, (datadump-table-column-queued), (datadump-table-column-in-progress), (datadump-table-column-completed), (datadump-table-column-failed)). If these messages are edited (which requires the (editinterface) right by default), anyone who can view Special:DataDump (which requires the (view-dump) right by default) can be XSSed. This vulnerability is fixed with 601688ee8e8808a23b102fa305b178f27cbd226d.
https://issue-tracker.miraheze.org/T12670
https://github.com/miraheze/DataDump/security/advisories/GHSA-h8x8-24c7-r2rj
https://github.com/miraheze/DataDump/commit/601688ee8e8808a23b102fa305b178f27cbd226d.patch