BizTalk Server 2010 CU5 version 3.9.556.2 was released on June 19, 2012.
Below is the KB article for BizTalk Server 2010 CU5
2689458 Cumulative update package 5 for BizTalk Server 2010

For more information about BizTalk Server CU update, please refer to the following link:

2555976 Service Pack and Cumulative Update list for BizTalk Server