Summary

This security update resolves a Microsoft SharePoint Server remote code execution vulnerability, and Microsoft SharePoint Server denial of service vulnerability. To learn more about the vulnerabilities, see the following security advisories:

Notes: 

  • This is build 16.0.10414.20002 of the security update package.

  • To apply this security update, you must have the release version of Microsoft SharePoint Server 2019 installed on the computer.

Improvements and fixes

This security update contains fixes for the following nonsecurity issues in SharePoint Server 2019:

  • Fixes the known issue in KB 5002615 in which some SharePoint PowerShell cmdlets don't function correctly because the Microsoft.SharePoint.ApplicationPages.SPThemes class is marked as unsafe in all Web.config files.

  • Fixes an issue in which the business data connectivity (BDC) features don't work correctly after you install the latest .NET cumulative updates.

Known issues in this update

  • After you apply this update, you might experience an issue that affects the deserialization of custom types that inherit from IDictionary. For more information, see Certain types that inherit from IDictionary are blocked from deserialization (KB5043462).

  • You might experience an issue in which SharePoint workflows can't be published because the unauthorized type is blocked. The issue also generates event tag "c42q0" in SharePoint Unified Logging System (ULS) logs. To work around this issue, register the safe types in the Web.config file. You can look for event tag "c42q0" in ULS logs to find the blocked type. If the type and assembly are safe, add the type to the authorized list in the Web.config file. For example:

    <System.Workflow.ComponentModel.WorkflowCompiler>    <authorizedTypes>      <targetFx version="v4.0">         <authorizedType Assembly="Microsoft.SharePoint.WorkflowActions, Version=16.0.0.0, Culture=neutral, PublicKeyToken=null" Namespace="Microsoft.SharePoint.WorkflowActions.WithKey" TypeName="*" Authorized="True" />     </targetFx>    </authorizedTypes>

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 Deployments - Security Update Guide.

Security update replacement information

This security update replaces previously released security update 5002615.

File hash information

File name

SHA256 hash

sts2019-kb5002639-fullfile-x64-glb.exe

97A7A3CC161A4AE62802A85312CBF62792395B8BA74323B2F43C2AC867BBFC88

File information

Download the list of files that are included in security update 5002639.

Information about protection and security

Protect yourself online: Windows Security support

Learn how we guard against cyber threats: Microsoft Security

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