Apple has issued Security Update 2010-002 (Mac OS X v10.6.3) that fixes 100 enumerated vulnerabilities in:
— Mac OS X 10.5
— Mac OS X 10.6
— Mac OS X Server 10.5
— Mac OS X Server 10.6

The 400 MB+ download takes a while, so, be prepared.

Info here: http://support.apple.com/kb/HT4077