An issue was discovered in DifferenceEngine.php in MediaWiki before 1.35.12, 1.36.x through 1.39.x before 1.39.5, and 1.40.x before 1.40.1. diff-multi-sameuser (aka "X intermediate revisions by the same user not shown") ignores username suppression. This is an information leak.
https://phabricator.wikimedia.org/T341529
https://lists.debian.org/debian-lts-announce/2023/11/msg00027.html