CVE-2026-93601

A flaw was found in rustls-webpki. This component incorrectly processes DNS (Domain Name System) name constraints for certificates asserting a wildcard name. This could allow a misissued wildcard certificate to be accepted for a domain that should be outside its permitted scope. Consequently, this bypass of name constraints could lead to incorrect certificate validation, potentially enabling an attacker to spoof a legitimate domain or perform man-in-the-middle attacks if they can obtain and use such a misissued certificate.

This vulnerability is rated as having a Low impact because exploitation demands strict preconditions, notably obtaining a cryptographically valid wildcard certificate that has been improperly issued by an authority subject to name constraints. Although multiple Red Hat offerings embed rustls-webpki for certificate path validation, the vulnerable evaluation occurs only after cryptographic signature checks succeed. Consequently, this flaw cannot be leveraged for arbitrary certificate spoofing without an existing trust misconfiguration or CA compromise.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.