Remote code execution affecting Microsoft SharePoint Server
A vulnerability affecting Microsoft SharePoint Server would allow an attacker to remotely execute arbitrary code on affected servers.
Description
Technical context and vulnerability details
Microsoft SharePoint Server is a collaboration and content management platform developed by Microsoft, widely deployed in enterprise environments for document sharing, intranet site management and collaborative work. This solution is affected by a vulnerability labeled CVE-2026-45659 resulting from untrusted data deserialization in the Microsoft Office SharePoint component. Exploitation of this vulnerability would allow an attacker with only site member permissions to remotely execute arbitrary code on the affected system. It is classified high with a severity score of 8.8 according to CVSS V3.1.
Potential Risks & Impact
Potential consequences upon exploitation
- Remote Arbitrary Code Execution;
- Privilege escalation on the compromised system;
- Unauthorized access to data;
- Complete compromise of SharePoint environment;
Affected systems
Products, components and targeted versions
- SharePoint Enterprise Server 2016 versions earlier than 16.0.5552.1002;
- SharePoint Server 2019 versions earlier than 16.0.10417.20128;
- SharePoint Server Subscription Edition versions prior to 16.0.19725.20280;
RECOMMENDED ACTIONS:
- Update Microsoft SharePoint Server to the latest stable version;
- Apply security patches released by Microsoft through Windows Update or the Microsoft Update Catalog;
- Restrict access permissions to SharePoint sites to what is strictly necessary, applying the principle of least privilege;
Sources & External Links
Vendor security advisories and documentation
Advisory Specifications
CSIRT Emergency Response
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