CVE intelligence

CVE-2026-66321

Vulnerability intelligence

Published Aug 4, 2026Sources checked Sep 28, 2026

9.6CRITICALCVSS out of 10

What this means

Review the available evidence

CVE-2026-66321 and is rated Critical severity with a CVSS score of 9.6. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

CISA KEVNot listedBased on the latest collected catalog

EPSS1.1%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-66321?

Access of resource using incompatible type ('type confusion') in Microsoft Edge (Chromium-based) allows an unauthorized attacker to execute code over a network.