Description of the security update for Outlook 2016: April 14, 2020

Applies to: Outlook 2016


This security update resolves a remote code execution vulnerability that exists if Microsoft Office incorrectly loads arbitrary type libraries. To learn more about the vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2020-0760.

Note To apply this security update, you must have the release version of Outlook 2016 installed on the computer.

Be aware that the update in the Microsoft Download Center applies to the Microsoft Installer (.msi)-based edition of Office 2016. It doesn't apply to the Office 2016 Click-to-Run editions, such as Microsoft Office 365 Home (see What version of Office am I using?).

Known issues

Some types of Visual Basic for Applications (VBA) references might be affected by this update. For more information, see FAQ for VBA solutions affected by April 2020 Office security updates.

Note This change in behavior is caused by a design change in Office. The new behavior is by design. Therefore, a fix is not necessary and no mitigation will be provided.

Improvements and fixes

This security update contains the following improvements and fixes:
  • Makes updates to the United Kingdom holidays in the Outlook holiday file (Outlook.HOL). If the United Kingdom holidays have been added to your Outlook Desktop calendar, delete the existing events before you apply this update. For more information about how to delete holidays, see Add holidays to your calendar in Outlook for Windows.
  • Fixes an issue that prevents users from reopening an .msg file after they drag and drop an attachment from that message.
  • Fixes an issue in which Outlook makes unnecessary requests to fetch web add-ins from Exchange.

How to get and install the update

Method 1: Microsoft Update

This update is available from Microsoft Update. When you turn on automatic updating, this update will be downloaded and installed automatically. For more information about how to get security updates automatically, see Windows Update: FAQ.

Method 2: Microsoft Update Catalog

To get the standalone package for this update, go to the Microsoft Update Catalog website.

Method 3: Microsoft Download Center

You can get the standalone update package through the Microsoft Download Center. Follow the installation instructions on the download page to install the update.

More Information

Security update deployment information

For deployment information about this update, see security update deployment information: April 14, 2020.

Security update replacement information

This security update replaces previously released security update 4484250.

File hash information

File name SHA1 hash SHA256 hash
outlook2016-kb4484274-fullfile-x64-glb.exe 32FF69A5453BB344BADC588FAB82AB3361EED47B A6D71A122492415BF3BC9E7DC4875FDEC521023D9CC495279D64DAB943189E96
outlook2016-kb4484274-fullfile-x86-glb.exe 6836A2A63152DDAB1D51293300DB7CB66308DCB0 9426A9D423A2384D79460F476F37B83C5F4AEB51854012F5D400C34C133E8273

File information

The English (United States) version of this software update installs files that have the attributes that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). The dates and times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and times may change when you perform certain operations on the files.

Information about protection and security

Protect yourself online: Windows Security support

Learn how we guard against cyber threats: Microsoft Security