The system stored procedure sp_execute_external_script and the dynamic management view sys.dm_exec_cached_plans can cause memory leaks in SQL Server 2016 and 2017.
This fix is included in the following cumulative updates for SQL Server:
About SQL Server builds
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out 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.
Learn about the terminology Microsoft uses to describe software updates.