Introduction
Privilege escalation in a cloud collaboration platform can give an attacker unauthorized access to sensitive business data and administrative controls. CVE-2025-59245 is a critical vulnerability in Microsoft SharePoint Online, the core Microsoft 365 component that organizations worldwide use for document management and collaboration. This summary covers what is known about the vulnerability as of November 2025, how it is classified, and where it sits in SharePoint's recent security record.
Technical information
CVE-2025-59245 is classified as an elevation of privilege vulnerability in Microsoft SharePoint Online. It has a CVSS score of 9.8, which is critical severity. Its root cause falls under CWE-502: Deserialization of Untrusted Data. This class of flaw occurs when an application deserializes data from an untrusted source without validating it properly, which can let an attacker manipulate object state or execute arbitrary code.
As of November 2025, no public source has published technical details, code snippets, or exploitation vectors for CVE-2025-59245. No public indicators of compromise or detection methods are available either.
Affected systems and versions
The affected product is Microsoft SharePoint Online. As of November 2025, no specific version numbers or configuration details have been published for CVE-2025-59245.
Vendor security history
Microsoft has long been the leading provider of enterprise productivity platforms, and SharePoint Online is a core part of Microsoft 365, used by millions of organizations. SharePoint has had several critical vulnerabilities in recent years, including deserialization and privilege escalation issues (see CVE-2025-53770). Microsoft usually responds quickly with patches and advisories. Similar flaws keep recurring, though, which shows how hard it is to secure complex, integrated cloud platforms.
