CVE-2026-56164: Microsoft SharePoint Server Missing Authentication for Critical Function Vulnerability

Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2026-07-14. EPSS: 1% chance of exploitation in the next 30 days.

Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.

Affected products

• Microsoft SharePoint Server: before 16.0.19725.20434 (fixed in 16.0.19725.20434); version 2016 only; version 2019 only

Published 2026-07-14. Last modified 2026-07-14.