CVE-2026-66805: Microsoft SharePoint Server Remote Code Execution Vulnerability
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
Other sources
Microsoft SharePoint Server Remote Code Execution Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.0.5565.1001Patch KB5002906 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.0.10417.20198Patch KB5002896 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.0.19725.20522Patch KB5002893
Event History
Frequently Asked Questions
What is the severity of CVE-2026-66805?
The severity of CVE-2026-66805 is rated as high with a score of 8.8.
How do I fix CVE-2026-66805?
To fix CVE-2026-66805, apply the latest security updates provided by Microsoft for SharePoint Server.
What type of vulnerability is CVE-2026-66805?
CVE-2026-66805 is a Remote Code Execution vulnerability caused by deserialization of untrusted data in Microsoft SharePoint.
What software is affected by CVE-2026-66805?
CVE-2026-66805 affects Microsoft SharePoint Server, SharePoint Server 2019, SharePoint Server Subscription Edition, and SharePoint Enterprise Server 2016.
Who can exploit CVE-2026-66805?
An authorized attacker with network access can exploit CVE-2026-66805 to execute arbitrary code.