critical9.8Known exploited
CVE-2026-20963
Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
Exploited in the wild
This vulnerability is on the CISA Known Exploited Vulnerabilities list, added 2026-03-18. Federal due date: 2026-03-21.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Impact
Microsoft SharePoint contains a deserialization of untrusted data vulnerability that allows an unauthorized attacker to execute code over a network.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Microsoft | Sharepoint Server | before 16.0.19127.20442 Versions 2016, 2019 |