Deserialization of Untrusted Data in Microsoft SharePoint Server and Microsoft SharePoint Enterprise Server - CVE-2026-45659
Published: May 27, 2026 / Updated: July 1, 2026
Vulnerability identifier: #VU132363
CSH Severity: High
CVSS v4.0: 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/E:A/U:Amber
CVE-ID: CVE-2026-45659
CWE-ID: CWE-502
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vendor: Microsoft
Affected software:
Microsoft SharePoint Server
Microsoft SharePoint Enterprise Server
Microsoft SharePoint Server
Microsoft SharePoint Enterprise Server
Detailed vulnerability description
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.
How to mitigate CVE-2026-45659
Install updates from vendor's website.