Missing Authentication for Critical Function in Microsoft SharePoint Server - CVE-2026-56164
Published: July 14, 2026 / Updated: August 6, 2026
Vulnerability identifier: #VU137541
CSH Severity: High
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-56164
CWE-ID: CWE-306
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vulnerability details
The vulnerability allows a remote attacker to gain unauthorized access to the application.
The vulnerability exists due to missing authentication for critical function. A remote non-authenticated attacker can send a specially crafted HTTP request and modify certain data.
Note, the vulnerability is being actively exploited in the wild.
Affected software
Microsoft SharePoint Server
How to mitigate CVE-2026-56164
Install updates from vendor's website.
Microsoft SharePoint Server - addressed in versions 16.0.5561.1001, 16.0.10417.20175, 16.0.19725.20434