Technically Microsoft recommends that you only install CU if you are impacted in an issue that the Cumulative Update corrects.CU may contain something that has unexpected side effects so you need to test your application with the CU before you change it in production.

A supported cumulative update package is now available from Microsoft. However, it is intended to correct only the problems that are described in this article. Apply it only to systems that are experiencing these specific problems. This cumulative update package may receive additional testing. Therefore, if you are not severely affected by any of these problems, we recommend that you wait for the next service pack that contains the hotfixes in this cumulative update package. 

http://www.sqlservercentral.com/blogs/databases-infrastructure-security/2014/05/28/do-you-apply-sql-server-cumulative-updates/

Service Packs are tested more rigorously than cumulative updates if no impact good to wait for SP3.

• Proposed as answer by Lydia ZhangMicrosoft contingent staff, Moderator 5 hours 23 minutes ago

Hi,

We are using SQL Server 2012 SP2 CU2. As of now we dont have any issues, but for a pro active approach, can I install CU5 based on the below Fixes which are included in CU5.

1. FIX: Performance issue occurs when you use sqlncli11.dll ODBC driver to access SQL Server in an application.

2. FIX: Complex parallel query does not respond in SQL Server 2012 or SQL Server 2014

3.  FIX: Rollback recovery on a snapshot fails when you run DBCC CHECKDB and then SQL Server shuts down unexpectedly.

Thanks,

FIX: Rollback recovery on a snapshot fails when you run DBCC CHECKDB and then SQL Server shuts down unexpec

Hello,

I agree with Dave. I prefer to apply service packs and apply fixes/cumulative updates only when I face performance issues or incidents.

Hope this helps.

Regards,

Alberto Morillo
SQLCoffee.com

• Proposed as answer by Lydia ZhangMicrosoft contingent staff, Moderator 5 hours 23 minutes ago

Hi,

Can I apply CU5 as a pro active approach for the below issue

FIX: Rollback recovery on a snapshot fails when you run DBCC CHECKDB and then SQL Server shuts down unexpectedly.

"This issue occurs because SQL Server tries to bring the affected database offline for error handling when a rollback recovery on a snapshot fails. However, the database cannot be offline because of the retained latch internally. Therefore, the SQL Server service is shut down."

Even I didn't face any issue so far, but since I run Checkdb on my production databases, so the condition mentioned in this FIX can occur. Also, since it shutdown the SQL Server, which is a serious point. can I apply this CU5 to avoid any potential risk?

Thanks.

CU may contain something that has unexpected side effects so you need to test your application with the CU before you change it in production. As long as you can test with your application and it has no side effects you can upgrade.