Mediawiki 1.16.3 was released [1] to correct three security flaws: Masato Kinugawa discovered a cross-site scripting (XSS) issue, which affects Internet Explorer clients only, and only version 6 and earlier. Web server configuration changes are required to fix this issue. Upgrading MediaWiki will only be sufficient for people who use Apache with AllowOverride enabled. (CVE-2011-1578) Wikipedia user Suffusion of Yellow discovered a CSS validation error in the wikitext parser. This is an XSS issue for Internet Explorer clients, and a privacy loss issue for other clients since it allows the embedding of arbitrary remote images. (CVE-2011-1579) MediaWiki developer Happy-Melon discovered that the transwiki import feature neglected to perform access control checks on form submission. The transwiki import feature is disabled by default. If it is enabled, it allows wiki pages to be copied from a remote wiki listed in $wgImportSources. The issue means that any user can trigger such an import to occur. (CVE-2011-1580) [1] http://lists.wikimedia.org/pipermail/mediawiki-announce/2011-April/000096.html
Created mediawiki tracking bugs for this issue Affects: fedora-all [bug 696361]
Created mediawiki116 tracking bugs for this issue Affects: epel-all [bug 696362]
*** Bug 695577 has been marked as a duplicate of this bug. ***
1.16.3 is not sufficient, as it does not fully fix the CVE-2011-1578 issue. Mediawiki 1.16.4 has been released to fully address it: http://lists.wikimedia.org/pipermail/mediawiki-announce/2011-April/000097.html
The issue noted in comment #4 (incomplete fix for CVE-2011-1578) has been assigned the name CVE-2011-1587.