MediaWiki before 1.23.15, 1.26.x before 1.26.4, and 1.27.x before 1.27.1 does not generate head items in the context of a given title, which allows remote attackers to obtain sensitive information via a parse action to api.php.Referenceshttps://phabricator.wikimedia.org/T139570https://lists.wikimedia.org/pipermail/mediawiki-announce/2016-August/000195.htmlhttps://bugzilla.redhat.com/show_bug.cgi?id=1369613https://phabricator.wikimedia.org/T139565
