Microsoft has released a bulletin to certain partners dated October 23, 2008 regarding a patch MS08-067 that patches a vulnerability in the server service that could allow remote code execution from an unauthenticated user. You can view more about it here: http://www.microsoft.com/technet/security/Bulletin/MS08-067.mspx
Altiris has worked through the night and released the update and if your pmimport.cab download has run for today, then you should see MS08-067 in Tasks> Software Management> Patch Management> Manage Software Updates.
If your pmimport.cab has not updated then you should manually kick off this job by going to Configuration> Software Management> Patch Management> Server Settings> Microsoft Settings and right click on Microsoft Patch Management Import and select Start download task from the menu.
If you left click on Microsoft Patch Management Import and click the History tab you can check your pmimport.cab version. 6.2.1236.1 is the version that contains the ms08-067 update. Once the pmimport.cab is updated you can head over to Tasks> Software Mangement> Patch Management> Manage Software Updates and Stage the MS08-067 update and then deploy to your defined collections.
I apologize for not having screenshots but this was important.