Available in Software Update.

Security Update 2005-007 delivers a number of security enhancements and is recommended for all Macintosh users. This update includes the following components:

AppKit
BlueTooth
CoreFoundation
cups
Directory Services
HIToolBox
Kerberos
loginwindow
Mail
OpenSSL
QuartzComposerScreenSaver
Security Interface
Safari
X11
zlib

For detailed information on this Update, please visit this website: http://www.info.apple.com/kbnum/n61798