An issue was discovered in MediaWiki before 1.35.11, 1.36.x through 1.38.x before 1.38.7, and 1.39.x before 1.39.4. BlockLogFormatter.php in BlockLogFormatter allows XSS in the partial blocks feature.
https://www.mediawiki.org/wiki/Release_notes/1.40#Other_changes_in_1.40
https://www.debian.org/security/2023/dsa-5447