CVE intelligence

CVE-2026-66808

Vulnerability intelligence

Published Aug 11, 2026Sources checked Oct 28, 2026

8.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-66808 and is rated High severity with a CVSS score of 8.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Aug 11, 2026

Install KB5002905. Install KB5002906. Install KB5002894. Install KB5002896. Install KB5002893.

Vendor-listed releases

16.0.5565.1001
16.0.10417.20198
16.0.19725.20522

CISA KEVNot listedBased on the latest collected catalog

EPSS2.0%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-66808?

Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.

Source: NVD