CVE-2026-20963

critical Microsoft ⚠️ CISA KEV — Exploited in the Wild
CVSS v3 Base Score
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
EPSS Score
6.2%
Exploitation probability in 30 days
Top 9% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Published: January 13, 2026 (121 days ago)
Last Modified: April 2, 2026
Vendor: Microsoft
Source: MITRE

⚠️ CISA Known Exploited Vulnerability

Added to KEV: 2026-03-18
Remediation Due: 2026-03-21 (⚠ 55d overdue)

Description

Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.

CWE

CWE-502

Affected Products

Microsoft Microsoft SharePoint Enterprise Server 2016Microsoft Microsoft SharePoint Server 2019Microsoft Microsoft SharePoint Server Subscription Edition

References

🔗 msrc.microsoft.com