Apple has released a security update for OS X Snow Leopard, Lion and Mountain Lion, Security Update 2013-003 for Snow Leopard, Lion and Mountain Lion. Apple's security update Knowledge Base article has not been updated with details about the release, but changes should appear soon.
About Security Update 2013-003 (Lion)
Security Update 2013-003 is recommended for all users and improves the security of OS X.
For information on the security content of this update, please visit this website: http://support.apple.com/kb/HT1222