Today I was testing CU7 for SQL Server 2012 SP2 and as usual after installing CU on our test server, as a practice I was reviewing the Error Log and interestingly it mentioned CU7 during the startup! Let me show you what am saying…See below screenshot on a server running SQL Server 2012 SP1+CU4. Till date SQL Server error log never revealed CU# in the start up entries…It just says the Service pack level which you’ve got.
Now with the CU7 for SQL 2012 SP2, that’s no longer the case 🙂 See below screenshot:
Even @@version from T-SQL is revealing the CU installed.
MSSQLTREK 
Installed CU7 on half of the cluster, and the program does not see a sql connection. SQL studio shows all instances up and running. Guess we will need to call MS or uninstall it and hope all works again.