KB5002825: This update fixes the GB18030-2022 China certification issue.

Description of the security update for SharePoint Server 2019: January 13, 2026 (KB5002825)

This security update resolves Microsoft Office Click-To-Run Elevation of Privilege vulnerability, Microsoft SharePoint Remote Code Execution vulnerability, Microsoft SharePoint Information Disclosure vulnerability, Microsoft Word Remote Code Execution vulnerability, Microsoft SharePoint Server Remote Code Execution vulnerability, and Microsoft SharePoint Server Spoofing vulnerability. To learn more about the vulnerabilities, see the following security advisories:

• Microsoft Common Vulnerabilities and Exposures CVE-2026-20943
• Microsoft Common Vulnerabilities and Exposures CVE-2026-20963
• ​​​​​​​Microsoft Common Vulnerabilities and Exposures CVE-2026-20948
• Microsoft Common Vulnerabilities and Exposures CVE-2026-20958​​​​​​​
• Microsoft Common Vulnerabilities and Exposures CVE-2026-20951​​​​​​​
• Microsoft Common Vulnerabilities and Exposures CVE-2026-20959
• ​​​​​​​Microsoft Common Vulnerabilities and Exposures CVE-2026-20947

Notes:

• This is build 16.0.10417.20083 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 improvements and fixes for the following nonsecurity issue in SharePoint Server 2019:

• This update fixes the GB18030-2022 China certification issue.
• This update fixes the data duplication issue that occurs during the Remote Blob Storage (RBS) migration.