Apple today released OS X 10.8.5 which is recommended for all OS X Mountain Lion users and improves the stability, compatibility, and security of your Mac.
• Fixes an issue that may prevent Mail from displaying messages
• Improves AFP file transfer performance over 802.11ac Wi-Fi
• Resolves an issue that may prevent a screen saver from starting automatically
• Improves Xsan reliability
• Improves reliability when transferring large files over Ethernet
• Improves performance when authenticating to an Open Directory server
• Addresses an issue that prevented a smart card from unlocking preference panes in System Preferences
• Contains the improvements included in MacBook Air (Mid 2013) Software Update 1.0
Detailed information about the security content of this update here.