Session fixation vulnerability in Special:UserLogin in MediaWiki before 1.18.6, 1.19.x before 1.19.3, and 1.20.x before 1.20.1 allows remote attackers to hijack web sessions via the session_id.
https://exchange.xforce.ibmcloud.com/vulnerabilities/83008
https://bugzilla.wikimedia.org/show_bug.cgi?id=40995
http://lists.wikimedia.org/pipermail/mediawiki-announce/2012-November/000122.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-March/100845.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-March/100843.html
http://lists.fedoraproject.org/pipermail/package-announce/2013-February/098975.html