CVE DATABASE / CVE-2026-20963
CVE-2026-20963
Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
CVSS 9.8 · CRITICAL
⚠ CISA KEV — ACTIVELY EXPLOITED
On the CISA KEV catalog
Confirmed exploited in the wild. Added 2026-03-18.
Federal remediation due 2026-03-21.
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.
Summary
Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
CVSS 3.1 breakdown
| Base score | 9.8 (CRITICAL) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| Attack vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity | HIGH |
| Availability | HIGH |
Weakness type (CWE)
Affected products
Microsoft sharepoint server
Check this CVE live
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References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20963
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20963
Data: NIST NVD + CISA KEV. NVD last modified 2026-04-01. Always verify against the vendor advisory before acting.