We recently published a new KB article that lists all of the cumulative updates that were released for Microsoft System Center 2012 Operations Manager Service Pack 1 (OpsMgr 2012 SP1). The updates are listed according to release date and include the associated build number. Also note the following:
Cumulative update build numbers with a larger numeric value include the fixes from all previously released cumulative updates.
Any version of OpsMgr 2012 Service Pack 1 can be updated to a later cumulative update.
You cannot uninstall a later-version cumulative update to downgrade to an earlier-version cumulative update.