CVE-2026-67294
FreeRDP before 3.29.0 TLS Certificate EKU Bypass
- State
- Published
- Severity
- 9.3 Critical
- Published
- Aug 1, 2026
- Updated
- Aug 3, 2026
- Reserved
- Jul 29, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 9.3 Critical | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 5.9 Medium | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N | VulnCheck |
Weaknesses
- CWE-295 Improper Certificate Validation
Affected Products
| Product | Versions |
|---|---|
FreeRDPFreeRDP |
|
References
- GitHub Security Advisory (GHSA-89c6-jjrw-96h4)vendor-advisory
- Patch Commitpatch
- VulnCheck Advisory: FreeRDP before 3.29.0 TLS Certificate EKU Bypassthird-party-advisory
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