KB5002840

Description of the security update for SharePoint Server 2016 Language Pack: February 10, 2026 (KB5002840)

Applies To

SharePoint Server 2016

Summary

Important:

• If you're running Microsoft SharePoint Server 2013-type workflows, you must install the August 2025 update for SharePoint Workflow Manager to your farm before you install this cumulative update.

• If you're currently running the Classic version of Workflow Manager, you must enable the debug flag to continue using it:

$farm = Get-SPFarm

$farm.ServerDebugFlags.Add(53601)

$farm.update()

iisreset

This security update resolves a Microsoft Outlook spoofing vulnerability and Microsoft Word spoofing vulnerability. To learn more about the vulnerability, see the following security advisories:

• Microsoft Common Vulnerabilities and Exposures CVE-2026-20948

• Microsoft Common Vulnerabilities and Exposures CVE-2026-21260

Notes:

• This is build 16.0.5539.1002 of the security update package.

• To apply this security update, you must have the release version of Microsoft SharePoint Server 2016 installed on the computer.

This public update delivers Feature Pack 2 for SharePoint Server 2016. Feature Pack 2 contains the following feature:

• SharePoint Framework (SPFx)

This public update also delivers all the features that were included in Feature Pack 1 for SharePoint Server 2016, including the following:

• Administrative Actions Logging

• MinRole enhancements

• SharePoint Custom Tiles

• Hybrid Taxonomy.

• OneDrive API for SharePoint on-premises

• OneDrive for Business modern user experience (available to Software Assurance customers)

The OneDrive for Business modern user experience requires an active Software Assurance contract at the time that the experience is enabled, either by installation of the public update or...