Remote Code Execution Vulnerability in Microsoft Office SharePoint
CVE-2026-66805

8.8HIGH

Key Information:

Vendor

Microsoft
Status
Microsoft Sharepoint Enterprise Server 2016
Microsoft Sharepoint Server 2019
Microsoft Sharepoint Server Subscription Edition
Vendor
CVE Published:
11 August 2026

What is CVE-2026-66805?

A security flaw exists in Microsoft Office SharePoint that permits an authorized attacker to exploit deserialization of untrusted data. This vulnerability enables the execution of arbitrary code over a network, potentially leading to unauthorized access and control over affected systems. Organizations using SharePoint should apply the latest security updates to mitigate this risk.

Affected Version(s)

Microsoft SharePoint Enterprise Server 2016 x64-based Systems 16.0.0 < 16.0.5565.1001

Microsoft SharePoint Server 2019 x64-based Systems 16.0.0 < 16.0.10417.20198

Microsoft SharePoint Server Subscription Edition x64-based Systems 16.0.0 < 16.0.19725.20522

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.