CVE intelligence

CVE-2026-42508

Vulnerability intelligence

Published May 22, 2026Sources checked Sep 27, 2026

9.1CRITICALCVSS out of 10

What this means

Review the available evidence

CVE-2026-42508 and is rated Critical severity with a CVSS score of 9.1. 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

EPSS0.7%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-42508?

Previously, a revoked 'SignatureKey' belonging to a CA was not correctly checked for revocation. Now, both the 'key' and 'key.SignatureKey' are checked for @revoked.