Summary
Important:
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If you're currently running SharePoint Workflow Manager, you must install the SharePoint Workflow Manager (KB5002799) to your farm before you install this cumulative update.
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If you're currently running the Classic version of Workflow Manager, you have to enable the debug flag in order to continue using it.$farm = Get-SPFarm
$farm.ServerDebugFlags.Add(53601)
$farm.update()
iisreset
This security update resolves a Microsoft Word spoofing vulnerability and Microsoft Outlook spoofing vulnerability. To learn more about the vulnerabilities, see the following security advisories:
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Microsoft Common Vulnerabilities and Exposures CVE-2026-21511
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Microsoft Common Vulnerabilities and Exposures CVE-2026-21260
Notes:
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This is build 16.0.10417.20097 of the security update package.
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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 improvements and fixes for the following nonsecurity issue in SharePoint Server 2019:
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Fixes the GB18030-2022 China certification issue.
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Fixes an issue in which the w3wp process stops responding repeatedly.
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Fixes an issue in which Set-SPMachineKey can no longer be used to set machine keys after the September 2025 cumulative update is installed.
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 5002825.
File hash information
|
File name |
SHA256 hash |
|---|---|
|
sts2019-kb5002834-fullfile-x64-glb.exe |
28B98ADCFF34D0D15D40281C85512507C122E059B189D9B42A52DB2A106511A3 |
File information
Download the list of files that are included in security update 5002834.
Information about protection and security
Protect yourself online: Windows Security support
Learn how we guard against cyber threats: Microsoft Security
