Description of the security update for Office Online Server: June 11, 2019


This security update resolves a remote code execution vulnerability that exists in Microsoft Word software if the program does not correctly handle objects in memory. To learn more about the vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2019-1034 and Microsoft Common Vulnerabilities and Exposures CVE-2019-1035.

Note To apply this security update, you must have the release version of Microsoft Office Online Server installed on the computer.

Known issues in this update

  • After you install this security update, Office Online Server logging will be set to Verbose by default. We recommend that you change this setting to Medium by running the following command:

    Set-OfficeWebAppsFarm -LogVerbosity “Medium”

    Note After you run the command, you have to restart the Office Online Service. To do this, run the following command:

    Restart-Service WACSM

Improvements and fixes

This security update contains a fix for the following nonsecurity issue:

  • Word documents cannot be viewed on mobile browsers in Office Online servers for certain language locales.

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 standalone 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: June 11, 2019.

Security update replacement information

This security update replaces previously released security update 4462169.

File hash information

File name SHA1 hash SHA256 hash
wacserver2019-kb4475511-fullfile-x64-glb.exe 40A05FBDFE260F0CB292BEDAC5AC2DE3C28F24B0 51567485A37E35CE41D31F38B325EB9C30F218FA4E997C6BD180DBC8F808ECF1

File information

Download the list of files that are included in security update 4475511.

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