CVE-2026-67294 Details
Description
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 vulnerability exists in FreeRDP versions through 3.28.0, where the application improperly validates the Extended Key Usage (EKU) of peer certificates during client-side server TLS authentication. This flaw allows a certificate intended only for client authentication, but issued by a trusted Certificate Authority (CA) and matching the hostname, to be accepted as a valid RDP server certificate. The issue arises because, after failing to verify a certificate for server purposes, the application incorrectly falls back to client and any-purpose verifications. This vulnerability can be exploited in environments that depend on EKU distinctions between client and server certificates.
Users can upgrade to FreeRDP version 3.29.0 or later, where this vulnerability has been patched.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Aug 3, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-89c6-jjrw-96h4 | CISA-ADP | ExploitVendor Advisory |
| https://github.com/FreeRDP/FreeRDP/commit/f3b4347105114fe7453828736bea069999af319f | [email protected] | Patch |
| https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-89c6-jjrw-96h4 | [email protected] | ExploitVendor Advisory |
| https://www.vulncheck.com/advisories/freerdp-before-tls-certificate-eku-bypass | [email protected] | PatchThird Party Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-295 | Improper Certificate Validation | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| freerdp freerdp | < 3.29.0 |
CPE
Remediation
| |
Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 11, 2026 | Initial Analysis | [email protected] |
| Aug 3, 2026 | CVE Modified | CISA-ADP |
| Aug 1, 2026 | New CVE Received | [email protected] |