The Mac OS X v10.6.3 update, which is considered "critical," covers flaws that could lead to remote code execution, information disclosure and denial-of-service attacks.
In some scenarios, a malicious hacker could take complete control of a Mac-powered machine if a user simply views a malicious image or movie file.
In another case, a Mac user running spell-check could have his/her machine hijacked by hackers.
The update covers critical vulnerabilities in AppKit, QuickTime,CoreMedia, CoreTypes, DiskImages, ImageIO and Image RAW.
It also covers holes in several open-source components, including Apache, ClamAV, MySQL, PHP.
Here's the full list of the patched vulnerabilities.
The Security Update 2010-002 / Mac OS X v10.6.3 may be obtained from the Software Update pane in System Preferences, or Apple's Software Downloads web page.