CVE-2026-88647

A flaw was found in GnuTLS. This vulnerability can lead to information disclosure by allowing an attacker to bypass certificate hostname verification. A remote attacker presenting a crafted certificate can circumvent the Common Name fallback check, enabling them to eavesdrop on or intercept encrypted network communications.

This vulnerability is rated as Moderate impact for Red Hat products because successful exploitation requires an active man-in-the-middle network position and specific certificate configurations to bypass trust validation. Although GnuTLS provides cryptographic transport across numerous system tools and client applications, contemporary TLS deployments largely rely on Subject Alternative Name (SAN) fields rather than legacy Common Name resolution. Consequently, the flaw cannot be triggered passively and necessitates an adversarial network posture combined with targeted certificate manipulation.

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.