After you enable the Change Data Capture feature on a large table in Microsoft SQL Server 2014, it takes a long time to install service packs (SPs) or cumulative updates (CUs) on the instance of SQL Server.
Cumulative update information
The issue was first fixed in the following cumulative update for SQL Server:
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. We recommend that you download and install the latest cumulative updates for SQL Server:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.