Symptoms
In a Microsoft Exchange Server 2013 environment, you notice that noderunner.exe is consuming excessive CPU resources. When this issue continues for a long time, users are eventually disconnected from Exchange Server.
Cause
This issue may occur because of regex matching when noderunner.exe parses an attachment, such as a Word document, in an email message.
Resolution
To fix this issue, install Cumulative Update 11 for Exchange Server 2013.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminology that Microsoft uses to describe software updates.
