CVE intelligence

CVE-2026-66807

Vulnerability intelligence

Published Aug 11, 2026Sources checked Oct 28, 2026

7.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-66807 and is rated High severity with a CVSS score of 7.8. 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 17, 2026

Click to Run Release Notes

Vendor-listed releases

https://aka.ms/OfficeSecurityReleases
16.112.26081010

CISA KEVNot listedBased on the latest collected catalog

EPSS0.5%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-66807?

Stack-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.

Source: NVD