KB5002840: This security update resolves a Microsoft Outlook spoofing vulnerability

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

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-2026-21511
• ​​​​​​​Microsoft Common Vulnerabilities and Exposures CVE-2026-21260

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 by manual enablement. If you don't have an active Software Assurance contract at the time of enablement, you must turn off the OneDrive for Business modern user experience.