CVE-2026-56164

Missing Authentication for Critical Function in Microsoft SharePoint Server. CISA confirmed attackers exploit it and added it to its Known Exploited Vulnerabilities catalog on 14 July 2026.

Product
Microsoft SharePoint Server
Added to CISA's catalog
Federal fix-by date
Ransomware
No known use in ransomware campaigns

CISA’s description.

Microsoft SharePoint contains a missing authentication for critical function vulnerability that allows an unauthorized attacker to elevate privileges over a network.

Every flaw CISA confirmed exploited in the last 30 days is on the exploit watch. This is not security advice. Check the vendor’s advisory before acting. From CISA’s catalog of 4 November 2026.