CVE-2026-66805: Microsoft SharePoint Server Remote Code Execution Vulnerability
Published Aug 11, 2026
·Updated
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
7 affected componentsFixes available
Microsoft SharePoint Server
Microsoft SharePoint Server Subscription Edition<16.0.19725.20522
16.0.19725.20522
Microsoft SharePoint Enterprise Server 2016<16.0.5565.1001
16.0.5565.1001
Microsoft SharePoint Server 2019<16.0.10417.20198
16.0.10417.20198
Microsoft SharePoint Server<16.0.19725.20522
Microsoft SharePoint Server=2016
Microsoft SharePoint Server=2019
Remediation
Event History
Aug 11, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
CVE Published
via MITRE·05:07 PM
Data Sourced
via MITRE·05:07 PM
DescriptionSeverity
Data Sourced
via NVD·05:19 PM
RemedyDescriptionSeverityWeaknessAffected Software
Frequently Asked Questions
1
What is the severity of CVE-2026-66805?
The severity of CVE-2026-66805 is rated as high with a score of 8.8.
2
How do I fix CVE-2026-66805?
To fix CVE-2026-66805, apply the latest security updates provided by Microsoft for SharePoint Server.
3
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.
4
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.
5
Who can exploit CVE-2026-66805?
An authorized attacker with network access can exploit CVE-2026-66805 to execute arbitrary code.