CVE-2026-67293

A flaw was found in FreeRDP, a free implementation of the Remote Desktop Protocol (RDP). The software's Transport Layer Security (TLS) hostname matcher incorrectly validates wildcard certificates, allowing it to accept certificates for multi-label subdomains that should not be covered. This vulnerability could enable a remote attacker to impersonate a legitimate server, potentially compromising the authenticity of the connection. This weakens the overall security of TLS server authentication.

This Moderate flaw in FreeRDP weakens TLS server authentication by incorrectly validating wildcard certificates. The client's TLS hostname matcher accepts multi-label subdomains (e.g., a.b.example.com) for a single-level wildcard (e.g., *.example.com), which deviates from standard OpenSSL behavior. This could allow a malicious RDP server to impersonate a legitimate server if a client attempts to connect to a subdomain covered by an improperly validated wildcard certificate.

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.