Description of the security update for Office Online Server: August 13, 2019

Applies to: Office Online Server


This security update resolves a remote code execution vulnerability that exists in Microsoft Word software if it does not correctly handle objects in memory. To learn more about the vulnerability, see Microsoft Common Vulnerabilities and Exposures CVE-2019-1201 and Microsoft Common Vulnerabilities and Exposures CVE-2019-1205.

Note To apply this security update, you must have the release version of 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 fixes the following issues in Office Online Server:

  • Fix: You can't share PowerPoint presentations through Skype for Business.
  • Fix: PowerPoint Online can't open files from SharePoint document libraries in Reading view .

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: August 13, 2019.

Security update replacement information

This security update replaces previously released security update 4475511.

File hash information

File name SHA1 hash SHA256 hash
wacserver2019-kb4475528-fullfile-x64-glb.exe 7007C757FEFB56FB3CECF7DFC0770ABC73A41FE3 3799687D877D405497A6F1921EA11DBDD699C4A48A13B023617DB67C1225EC4F

File information

Download the list of files that are included in security update 4475528.

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