WordPress 3.6.1 Maintenance and Security Release

WordPress 3.6.1 is also a security release for all previous WordPress versions and we strongly encourage you to update your sites immediately. It addresses three issues fixed by the WordPress security team:

• Block unsafe PHP unserialization that could occur in limited situations and setups, which can lead to remote code execution. Reported by Tom Van Goethem.
• Prevent a user with an Author role, using a specially crafted request, from being able to create a post “written by” another user. Reported by Anakorn Kyavatanakij.
• Fix insufficient input validation that could result in redirecting or leading a user to another website. Reported by Dave Cummo, a Northrup Grumman subcontractor for the U.S. Centers for Disease Control and Prevention.

Additionally, we’ve adjusted security restrictions around file uploads to mitigate the potential for cross-site scripting.

http://wordpress.org/news/2013/09/wordpress-3-6-1/