Sun has not released an updated package for the Solaris Security Toolkit (aka JASS) for quite a while now and it remains at version 4.2 on the official web site. Instead they have been releasing patches. The latest (122608-06) of which is now available for download from Sunsolve.
The timing of the patch releases usually coincide with each Solaris 10 update release. It is worthwhile keeping up to date with these patches as they cater for changes made to the OS with each update such as new and/or removed SMF services, Secure By Default, etc.