Outlook 2016 Security Update for September 2017

A Security Update has been released for Outlook 2016. In addition to resolving the vulnerabilities, it also contains 8 documented improvements and fixes.

Most notable fixes and improvements are:

  • Defense-in-depth update as mentioned in Security Advisory ADV170015. This is a general security update that is not specific to any current exploit.
  • Introduces the RequireADAL Registry value to prevent Outlook from connecting to Exchange servers that do not use ADAL.
  • When you try to add data to a profile through the Mail Applet in Control Panel, you receive the following error message;
    • An unknown error occurred, error code: 0x8000ffff.
  • After you mark an item as read in an IMAP folder in Outlook 2016, the item is changed to unread.

View: Download information for KB4011091

Note: This update can be installed via Microsoft Update or the Update Now button when you are using Office 365 and updates Outlook to version 16.0.4588.1000 (msi-based installation) or 16.0.8326.2107 (Office 365 based installation) or 16.0.8201.2193 (Office 365 Deferred Channel installation).