CVE-2026-20963: Microsoft SharePoint Deserialization of Untrusted Data Vulnerability

Added to the CISA Known Exploited Vulnerabilities catalog on 18 Mar 2026. Vendor: Microsoft. Product: SharePoint.

Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network.

Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. (due 21 Mar 2026)