Improper Certificate Validation in FreeRDP - #VU137821
Published: July 16, 2026
Vulnerability identifier: #VU137821
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: N/A
CWE-ID: CWE-295
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: FreeRDP
Affected software:
FreeRDP
FreeRDP
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass TLS server identity validation.
The vulnerability exists due to improper certificate validation in tls_verify_certificate() when verifying certificates where the Common Name matches but DNS subject alternative name entries are present and non-matching. A remote attacker can present a specially crafted certificate to bypass TLS server identity validation.
Exploitation requires a certificate chain trusted by the FreeRDP client.
Remediation
Install security update from vendor's website.