CVE-2026-50522

Deserialization of Untrusted Data in Microsoft SharePoint. CISA confirmed attackers exploit it and added it to its Known Exploited Vulnerabilities catalog on 22 July 2026.

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

CISA’s description.

Microsoft SharePoint contains a deserialization of untrusted data vulnerability which could allow an unauthorized attacker to execute code 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.