Apple has released Security Update 2007-004 for Mac OS X today.
Security Update 2007-004 is recommended for all users and improves the security of the following components:
AFP Client, AirPort, CarbonCore, diskdev_cmds, fetchmail, ftpd, gnutar, Help Viewer, HID Family, Installer, Kerberos, Libinfo, Login Window, network_cmds, SMB, System Configuration, URLMount, Video Conference, WebDAV