CVE-2026-6731: wolfSSL

High severity, CVSS 7.5. EPSS: 0.1% chance of exploitation in the next 30 days.

X.509 name constraint bypass via the Subject Common Name when treated as a DNS-type name. A certificate whose Subject CN violates an issuing CA's DNS name constraints could be accepted.

Affected products

• wolfSSL wolfSSL: from 3.9.10, before 5.9.2 (fixed in 5.9.2)

Published 2026-06-25. Last modified 2026-06-27.