CVE-2026-66808: 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
6 affected componentsFixes available
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
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-2026-66808?
CVE-2026-66808 has a severity rating of 8.8, categorized as high.
2
How do I fix CVE-2026-66808?
To fix CVE-2026-66808, apply the available patches from Microsoft for affected SharePoint versions.
3
What types of software are affected by CVE-2026-66808?
CVE-2026-66808 affects Microsoft SharePoint Server, including Subscription Editions and SharePoint Enterprise Server 2016 and 2019.
4
What kind of attack can be executed via CVE-2026-66808?
CVE-2026-66808 allows an authorized attacker to execute remote code over a network due to deserialization of untrusted data.
5
When was CVE-2026-66808 published?
CVE-2026-66808 was published on August 11, 2026.