Description of the security update for Outlook 2016: January 9, 2018

Applies to: Outlook 2016


This security update resolves vulnerabilities in Microsoft Office that could allow remote code execution if a user opens a specially crafted Office file. To learn more about these vulnerabilities, see Microsoft Common Vulnerabilities and Exposures CVE-2018-0791.

Note To apply this security update, you must have the release version of Microsoft 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 Determining your Office version).

Improvements and fixes

This security update contains improvements and fixes for the following nonsecurity issues:
  • In Microsoft Outlook 2016, when you select multiple attachments and try to cancel one of the attachments, all the other attachments are cancelled.
  • Some attachments are not removed when you forward mails that contain inline images and you check the Read all mails as Plain Text check box.

Known issues

Known issues in this security update

  • After you install this security update, attachments are removed when you forward plain text emails.

    To work around this issue, save the attachments locally, reattach, and then send the email.
    1. Save the attachments to a temporary location.
    2. Open the email, and then select Reply, Reply All, or Forward.
    3. Add the attachments that you saved in step 1.
    4. Send the email.
    To resolve this issue, install the January 22, 2018 update for Outlook 2016 (KB4011123)

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 stand-alone package for this update, go to the Microsoft Update Catalog website.

Method 3: Microsoft Download Center

You can get the stand-alone 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: January 9, 2018.

Security update replacement information

This security update replaces previously released security update KB 4011162.

File hash information

Package Name Package Hash SHA 1 Package Hash SHA 2
outlook2016-kb4011626-fullfile-x64-glb.exe 5A11B19DAC71A3A5D6FBDF6EB8A3B44CC5D18DAE 5B8BDBB8664EB930BB6CB0DA7C20523365D021A5037D121AE9D54EA53F3EB907
outlook2016-kb4011626-fullfile-x86-glb.exe 96949CEF219CA73B3B5DA3DBF77F6EDA1DA8377A 5638F398EF0B4AC58E19957477E22FA788C09E35782DC95C145F63D2392C400F

File information

The English version of this security update has the file attributes (or later file 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.

How to get help and support for this security update

Help for installing updates: Windows Update FAQ

Security solutions for IT professionals: Security Support and Troubleshooting

Help for protecting your Windows-based computer from viruses and malware: Microsoft Secure

Local support according to your country: International Support

Propose a feature or provide feedback on Office Core: Office User Voice portal