TLS Authentication Bypass in FreeRDP Affects Client and Server Certificates
CVE-2026-67294

9.3CRITICAL

Key Information:

Vendor

Freerdp

Status
Freerdp
Vendor
CVE Published:
1 August 2026

What is CVE-2026-67294?

FreeRDP versions prior to 3.29.0 exhibit an issue in client-side server TLS authentication where the Extended Key Usage (EKU) purpose of a peer certificate is not properly validated. Specifically, if the server-purpose verification fails, the system defaults to less restrictive client-purpose and any-purpose checks. This flaw allows an improperly verified, hostname-matching clientAuth-only certificate—trusted by a Certificate Authority—to be accepted as a valid RDP server certificate, undermining the integrity of the authentication mechanism in environments that enforce strict EKU separation between certificates.

Affected Version(s)

FreeRDP 0 < 3.29.0

FreeRDP 3.29.0

References

https://github.com/FreeRDP/FreeRDP/security/advisories/GH...
vendor-advisory
https://github.com/FreeRDP/FreeRDP/commit/f3b4347105114fe...
patch
https://www.vulncheck.com/advisories/freerdp-before-tls-c...
third-party-advisory

CVSS V4

Score:
9.3
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

1121984919
.