Today Apple released updates for Safari on Lion, Mountain Lion and Mavericks. All users are recommended to update.
The update addresses 7 webkit memory corruption issues that could lead to arbitrary code execution when visiting a malicious crafted website.
The updates can be obtained by running Software Update from the apple menu or opening the Updates tab of the Mac App Store.
Yesterday, patch tuesday, security updates were released for Adobe Flash Player, Adobe Reader and Adobe AIR.
If you have any of these products installed, check for updates as soon as you can. More information can be found here.