CVE-2026-67294
FreeRDP before 3.29.0 TLS Certificate EKU Bypass
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.
INFO
Published Date :
Aug. 1, 2026, 1:16 p.m.
Last Modified :
Sept. 11, 2026, 9:03 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 4.0 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update FreeRDP to version 3.29.0 or later.
- Ensure server certificates have the correct EKU purpose.
- Reconfigure TLS settings if EKU separation is critical.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-67294.
| URL | Resource |
|---|---|
| https://github.com/FreeRDP/FreeRDP/commit/f3b4347105114fe7453828736bea069999af319f | Patch |
| https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-89c6-jjrw-96h4 | Exploit Vendor Advisory |
| https://www.vulncheck.com/advisories/freerdp-before-tls-certificate-eku-bypass | Patch Third Party Advisory |
| https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-89c6-jjrw-96h4 | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-67294 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-67294
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-67294 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-67294 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Sep. 11, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:* versions up to (excluding) 3.29.0 Added Reference Type VulnCheck: https://github.com/FreeRDP/FreeRDP/commit/f3b4347105114fe7453828736bea069999af319f Types: Patch Added Reference Type VulnCheck: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-89c6-jjrw-96h4 Types: Exploit, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-89c6-jjrw-96h4 Types: Exploit, Vendor Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/freerdp-before-tls-certificate-eku-bypass Types: Patch, Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 03, 2026
Action Type Old Value New Value Added Reference https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-89c6-jjrw-96h4 Added SSVC {'id': 'CVE-2026-67294', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-03T18:15:07.050186Z'} -
New CVE Received by [email protected]
Aug. 01, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'FreeRDP', 'product': 'FreeRDP', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '3.29.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '3.29.0', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-295 Added Reference https://github.com/FreeRDP/FreeRDP/commit/f3b4347105114fe7453828736bea069999af319f Added Reference https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-89c6-jjrw-96h4 Added Reference https://www.vulncheck.com/advisories/freerdp-before-tls-certificate-eku-bypass