Description of the security update for Outlook 2016: January 8, 2019

Applies to: Outlook 2016


This security update resolves an information disclosure vulnerability that exists when Microsoft Outlook improperly handles certain types of messages. To learn more about the information disclosure vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2019-0559.

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 Determining your Office version).

Improvements and fixes

This security update contains the following improvements:

  • Improves the stability of Microsoft Outlook 2016.

  • Improves the Estonian translation of the Compact Navigation checkbox in the Navigation Options dialog box.

  • Improves Dutch translations in the Outlook profile dialog box when you start Outlook 2016 in safe mode.

  • Improves German translations of the text in the info bar that displays current voting results in an email message that has voting buttons.

  • Adds support for the Do Not Forward policy for meetings so that the meetings can't be forwarded by attendees.

This security update contains fixes for the following nonsecurity issues:

  • An email message that's saved as a plain text file will no longer have its message header field length vary based on the user's dots-per-inch (DPI) setting. This update fixes an issue with very narrow message header fields in high-DPI environments.

  • After update KB 3118388 is applied, Office documents in Public Folders are unexpectedly opened in Protected View.

  • A "Blocked external content" warning for Secure/Multipurpose Internet Mail Extensions (S/MIME) email messages that have no external content is displayed in Outlook 2016.

  • When Outlook 2016 replies to a plain text email with an invalid code page, message headers in the body of a reply or forward email message are displayed incorrectly.

  • When you access the Conversation History folder, Outlook 2016 hangs.

  • When you forward an email message that contains inline attachments, the inline attachments may be attached as files in the new email message.

  • When you open a custom form from the Organizational Forms Library, you experience a "Form load failed" error.

  • This update fixes Outlook issues in Agave apps for 11 languages (Bulgarian, Dutch, Estonian, French, Greek, Hindi, Latvian, Lithuanian, Portuguese [Brazilian], Russian, and Spanish).

  • Mail delivery rules stop working. When you try to open the Manage Rules and Alerts dialog box, you receive the following error message:

    The operation failed because of a registry or installation problem. Restart Outlook and try again. If the problem persists, reinstall.

How to get and install the update

Method 1: Microsoft Update

This update is available through Windows Update. When you turn on automatic updating, this update will be downloaded and installed automatically. For more information about how to turn on automatic updating, 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 8, 2019.

Security update replacement information

This security update replaces any previously released update KB 4461544.

File hash information

File name SHA1 hash SHA256 hash
outlook2016-kb4461601-fullfile-x86-glb.exe 35F4E857D01657E31217E2C16DEA43B3A38235C3 52285C91DACF349719BF99FAB558B44C403EF73DA2C9E9ED77347D89BAE4E23C
outlook2016-kb4461601-fullfile-x64-glb.exe BF1B99B7C78AAA7A42E3812D8BF59260EB9E6A36 369CB56E5CF6CBD20CAEBA7AD05B13AC3280CD7CE7F5E0D9FB97AE4E63B50897

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.

How to get help and support for this security update

Help for installing updates: Protect yourself online

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

Local support according to your country: International Support