Symptoms
When you execute a query for which you don't have sufficient permissions to perform operations, a memory leak occurs in the MEMOBJ_SOSNODE type object in Microsoft SQL Server 2014 or 2016.
Note The memory leak depends on how frequently the query restarts. The only way to release memory is to restart your instance of SQL Server.
Resolution
This issue is fixed in the following cumulative updates for SQL Server:
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Reference
Learn about the terminology Microsoft uses to describe software updates.