Deserialization of Untrusted Data in Microsoft SharePoint Server and Microsoft SharePoint Server Subscription Edition - CVE-2026-65665
Published: August 11, 2026
Vulnerability identifier: #VU141471
CSH Severity: Medium
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-2026-65665
CWE-ID: CWE-502
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to insecure input validation when processing serialized data in Microsoft SharePoint Server. A remote 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 Server
Microsoft SharePoint Server Subscription Edition
Microsoft SharePoint Server Subscription Edition
How to mitigate CVE-2026-65665
Install updates from vendor's website.
Microsoft SharePoint Server - update to 16.0.10417.20198
Microsoft SharePoint Server Subscription Edition - update to 16.0.19725.20522
Microsoft SharePoint Server Subscription Edition - update to 16.0.19725.20522