This issue occurs when applications that use the sessionStorage content from multiple Internet Explorer 11 WebBrowser control instances run on the same or single thread. When this issue occurs, the CPU and memory usage also become high.
To resolve this issue, install the most recent cumulative security update for Internet Explorer. To do this, go to Microsoft Update. Additionally, see the technical information about the most recent cumulative security update for Internet Explorer.
Note This update was first included in the Description of the security update for Internet Explorer: July 14, 2015 (MS15-065).
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
See the terminology that Microsoft uses to describe software updates.