Red Hat Multicluster Engine for Kubernetes cluster-proxy-addon improper authorization

Summaryinfo

A vulnerability, which was classified as critical, was found in Red Hat Multicluster Engine for Kubernetes. Affected by this issue is some unknown functionality of the component cluster-proxy-addon. Executing a manipulation can lead to improper authorization. This vulnerability is tracked as CVE-2026-66794. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability was found in Red Hat Multicluster Engine for Kubernetes (affected version not known). It has been declared as critical. This vulnerability affects some unknown functionality of the component cluster-proxy-addon. The manipulation with an unknown input leads to a improper authorization vulnerability. The CWE definition for the vulnerability is CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at access.redhat.com. This vulnerability was named CVE-2026-66794 since 07/27/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 08/19/2026). This vulnerability is assigned to T1548.002 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Virtualization Software

Vendor

• Red Hat

Name

• Multicluster Engine for Kubernetes

License

• open-source

Website

• Vendor: https://www.redhat.com/

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