CVE-2026-66794
Cluster-proxy-addon: cluster-proxy-addon: unauthenticated ssrf to arbitrary managed-cluster services via public route
A flaw was found in the cluster-proxy-addon component of Multicluster Engine for Kubernetes. This vulnerability allows an unauthenticated attacker, who can access the user-facing route, to bypass authentication and authorization checks. By manipulating URL path segments, the attacker can proxy requests to arbitrary services across any managed cluster. This enables unauthorized access to internal services that would otherwise be protected, potentially leading to information disclosure or further compromise of the cluster environment.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
9.3
Cluster-proxy-addon: cluster-proxy-addon: unauthenticated ssrf to arbitrary managed-cluster services via public route
A flaw was found in the cluster-proxy-addon component of Multicluster Engine for Kubernetes. This vulnerability allows an unauthenticated attacker, who can access the user-facing route, to bypass authentication and authorization checks. By manipulating URL path segments, the attacker can proxy requests to arbitrary services across any managed cluster. This enables unauthorized access to internal services that would otherwise be protected, potentially leading to information disclosure or further compromise of the cluster environment.
- Record
CVE-2026-66794- CVSS 3.1
- 9.3 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N - Weakness
- CWE-918
- Updated
- 2026-11-02
EUVDEUVD-2026-62598
9.3
A flaw was found in the cluster-proxy-addon component of Multicluster Engine for Kubernetes. This vulnerability allows an unauthenticated attacker, who can access the user-facing route, to bypass authentication and authorization checks. By manipulating URL path segments, the attacker can proxy requests to arbitrary services across any managed cluster. This enables unauthorized access to internal services that would otherwise be protected, potentially leading to information disclosure or further compromise of the cluster environment.
- Record
EUVD-2026-62598- CVSS 3.1
- 9.3 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-9855-9cch-x8mw
9.3
A flaw was found in the `cluster-proxy-addon` component of Multicluster Engine for Kubernetes....
A flaw was found in the cluster-proxy-addon component of Multicluster Engine for Kubernetes. This vulnerability allows an unauthenticated attacker, who can access the user-facing route, to bypass authentication and authorization checks. By manipulating URL path segments, the attacker can proxy requests to arbitrary services across any managed cluster. This enables unauthorized access to internal services that would otherwise be protected, potentially leading to information disclosure or further compromise of the cluster environment.
- Record
GHSA-9855-9cch-x8mw- CVSS 3.1
- 9.3 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N - Weakness
- CWE-918
- Updated
- 2026-11-02
NVD
9.3
A flaw was found in the cluster-proxy-addon component of Multicluster Engine for Kubernetes. This vulnerability allows an unauthenticated attacker, who can access the user-facing route, to bypass authentication and authorization checks. By manipulating URL path segments, the attacker can proxy requests to arbitrary services across any managed cluster. This enables unauthorized access to internal services that would otherwise be protected, potentially leading to information disclosure or further compromise of the cluster environment.
- Record
CVE-2026-66794- CVSS 3.1
- 9.3 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N - Weakness
- CWE-918
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-66794 is a critical vulnerability (CVSS 9.3) in Red Hat Multicluster Engine For Kubernetes 2.10, published August 19, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.62%, the 50th percentile. No source names a fixed version.