Copyright © 2012 Red Hat, Inc. All rights reserved. Low 2026-08-01T12:22:17 FreeRDP: FreeRDP: Server certificate validation bypass via improper Extended Key Usage (EKU) validation 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N CWE-295

FreeRDP before 3.29.0 improperly validates the Extended Key Usage (EKU) purpose of the peer certificate during client-side server TLS authentication. In x509_utils_verify(), when server-purpose (X509_PURPOSE_SSL_SERVER) verification fails, the code falls back to client-purpose and any-purpose verification, so a trusted, hostname-matching certificate valid only for clientAuth can be accepted as the RDP server certificate. In environments relying on EKU separation between client and server certificates, this allows a clientAuth-only certificate issued by a trusted CA to bypass server certificate purpose validation.

A flaw was found in FreeRDP. During client-side server Transport Layer Security (TLS) authentication, FreeRDP improperly validates the Extended Key Usage (EKU) purpose of the peer certificate. This vulnerability allows a certificate intended only for client authentication to be accepted as a server certificate, bypassing critical server certificate purpose validation. This could lead to an attacker presenting a clientAuth-only certificate from a trusted Certificate Authority (CA) to impersonate a legitimate server.

Red Hat Enterprise Linux 10 Fix deferred freerdp Red Hat Enterprise Linux 6 Out of support scope freerdp Red Hat Enterprise Linux 7 Out of support scope freerdp Red Hat Enterprise Linux 8 Fix deferred freerdp Red Hat Enterprise Linux 9 Fix deferred freerdp https://www.cve.org/CVERecord?id=CVE-2026-67294 https://nvd.nist.gov/vuln/detail/CVE-2026-67294 https://github.com/FreeRDP/FreeRDP/commit/f3b4347105114fe7453828736bea069999af319f https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-89c6-jjrw-96h4 https://www.vulncheck.com/advisories/freerdp-before-tls-certificate-eku-bypass