DescriptionSemantic MediaWiki 2.4.0 before 7.4.1 contains a reflected cross-site scripting vulnerability in TimeValueFormatter::getCaptionFromFreeFormat(), which emits free-format date captions in HTML without escaping. Unauthenticated attackers can craft a Special:Ask URL with HTML markup in a date printout format (#-F[...]) to execute script in a logged-in victim's browser session.