The model of delivery patch for Microsoft SQL server follows a very precise process that is described in the following article : http://support.microsoft.com/kb/935897/ 

We always recommend applying the latest Service Pack (SP) for SQL. However, you should apply it only after validation on your test platform.

- How to obtain the latest service pack for SQL Server 2000
- How to obtain the latest service pack for SQL Server 2005
- How to obtain the latest service pack for SQL Server 2008 
- How to obtain the latest service pack for SQL Server 2008 R2 
- How to obtain the latest service pack for SQL Server 2012

What is the policy of publication of the cumulative update?

The Cumulative Updates (CU) should be applied that knowledge to question, to address a specific issue (pro-active or re-active). The systematic application of the last internal CU can lead to changes in unwanted behavior of SQL Server.

Lifecycle Supported Service Packs http://support.microsoft.com/gp/lifesupsps   - Mainstream

 

SQL Server build : Last update : 17th September 2013
  
SQL 2012   
11 SP1 CU6 11.0.3381
11 SP1 CU5 11.0.3373
11 SP1 CU3 11.0.3349
11 SP1 CU2 11.0.3339 RECOMMENDED BUILD
11 SP1 CU1 11.0.3321
11 SP1 11.00.3000 
   
11 RTM CU8 11.0.2410
11 RTM CU7 11.0.2405
11 RTM CU5 11.0.2395
11 RTM CU4 11.0.2383
11 RTM CU3 11.0.2332
11 RTM CU2 11.0.2325
11 RTM CU1 11.0.2316
11 RTM 11.00.2100.60
11 RC0 11.0.1750.32
  
SQL 2008 R2   
10.5 SP2 CU6 10.50.4279
10.5 SP2 CU4 10.50.4270
10.5 SP2 CU3 10.50.4266
10.5 SP2 CU2 10.50.4263
10.5 SP2 CU1 10.50.4260
10.5 SP2 10.50.4000RECOMMENDED BUILD
   
| Microsoft EMEA
Product Support Services Developer - SQL Server Core Engineer |