March 18, 2026 · Applied Cybernetics Group
CVE-2026-20963 — Microsoft SharePoint
Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
- Added to KEV
2026-03-18- Federal due date
2026-03-21- Vendor
- Microsoft
- Product
- SharePoint
- EPSS
- 98.0th percentile (score 0.294, as of
2026-07-13) - NVD CVSS v3.1
- 9.8 (CRITICAL)
- Ransomware use
- Unknown
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2026-20963
CISA short description
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.
NVD description
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.