CVE intelligence

CVE-2026-27137

Vulnerability intelligence

Published Mar 6, 2026Sources checked Oct 3, 2026

7.5HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-27137 and is rated High severity with a CVSS score of 7.5. 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

CBL-Mariner Releases

Vendor-listed releases

1.25.8-1
1.26.1-1

CISA KEVNot listedBased on the latest collected catalog

EPSS0.7%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-27137?

When verifying a certificate chain which contains a certificate containing multiple email address constraints which share common local portions but different domain portions, these constraints will not be properly applied, and only the last constraint will be considered.