The Exchange Team has released update rollup 2 for Exchange 2010 SP3.
This update rollup does not apply to Exchange Server 2010 RTM, SP1 or SP2. You should have atleast Exchange 2010 SP3 running.
The following update rollups have also been released today.
- Update Rollup 11 for Exchange Server 2007 SP3
- Update Rollup 7 for Exchange Server 2010 SP2
- Exchange Server 2013 RTM CU1 MSRC Security bulletin MS13-061
- Exchange Server 2013 RTM CU2 MSRC Security bulletin MS13-061
Check the source for more info.