KB5002657: Fixes an issue that affects restricting SPSerialization

Description of the security update for SharePoint Server 2019: December 10, 2024 (KB5002657)

Summary
This security update resolves a Microsoft SharePoint remote code execution vulnerability, Microsoft SharePoint elevation of privilege vulnerability, Microsoft SharePoint information disclosure vulnerability, and Microsoft Office remote code execution vulnerability. To learn more about the vulnerabilities, see the following security advisories:

• Microsoft Common Vulnerabilities and Exposures CVE-2024-49070
• Microsoft Common Vulnerabilities and Exposures CVE-2024-49068
• Microsoft Common Vulnerabilities and Exposures CVE-2024-49064
• Microsoft Common Vulnerabilities and Exposures CVE-2024-49062
• Microsoft Common Vulnerabilities and Exposures CVE-2024-49065

Notes:

• This is build 16.0.10416.20026 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 a fix for the following nonsecurity issue in SharePoint Server 2019:

• Fixes an issue that affects restricting SPSerialization by using a new allow list mechanism. This cause pages that have third-party web parts or controls not to load successfully. For more information, see Nested third-party web parts or controls experience display problems (KB5049566).

This security update also contains an improvement. To get the improvement, you have to install KB 5002664 together with this update.

• Adds a banner in Central Administration to notify customers about the end of support for Search Content Service (SCS)-based hybrid search.