Main Vulnerability Database Vulnerabilities #VU132363

Deserialization of Untrusted Data in Microsoft SharePoint Enterprise Server and Microsoft SharePoint Server - CVE-2026-45659

Published: May 27, 2026 / Updated: July 1, 2026

Vulnerability identifier: #VU132363

CSH Severity: High

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-45659

CWE-ID: CWE-502

Exploitation vector: Remote access

Exploit availability: The vulnerability is being exploited in the wild

Vulnerability details

The vulnerability allows a remote user to execute arbitrary code on the target system.

The vulnerability exists due to insecure input validation when processing serialized data. A remote authenticated user can pass specially crafted data to the application and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Affected software

Microsoft SharePoint Enterprise Server
Microsoft SharePoint Server

How to mitigate CVE-2026-45659

Install updates from vendor's website.

Microsoft SharePoint Enterprise Server - update to 16.0.5552.1002
Microsoft SharePoint Server - addressed in versions 16.0.10417.20128, 16.0.19725.20280

External References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45659

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