CVE-2026-67294
Low
No strong exploitation signal.
CVSS base
5.9
MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS — probability of exploitation (30 days)
0.3%
18.7th percentile
CISA KEV
Not listed
Weakness / dates
CWE-295
Published 2026-08-01 · modified 2026-09-11
CVSS breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
| Attack Vector | N | Network |
| Attack Complexity | H | High |
| Privileges Required | N | None |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | N | None |
| Availability | N | None |
Timeline
- 2026-08-01 — Published (NVD)
- 2026-09-11 — Last modified (NVD)
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.
Affected
References
- https://github.com/FreeRDP/FreeRDP/commit/f3b4347105114fe7453828736bea069999af319f
- exploit https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-89c6-jjrw-96h4
- https://www.vulncheck.com/advisories/freerdp-before-tls-certificate-eku-bypass
- exploit https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-89c6-jjrw-96h4