Description
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.
References8
- access.redhat.com/errata/RHSA-2026:59556
- access.redhat.com/errata/RHSA-2026:59557
- access.redhat.com/errata/RHSA-2026:59558
- access.redhat.com/errata/RHSA-2026:59559
- access.redhat.com/errata/RHSA-2026:59579
- access.redhat.com/errata/RHSA-2026:59593
- access.redhat.com/security/cve/CVE-2026-66794
- bugzilla.redhat.com/show_bug.cgi?id=2507539
Metrics
- CVSS 3.1
-
9.3
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N - EPSS — exploit probability
- 1% percentile: 50 · as of 10 November 2026
- CWE
- CWE-918
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.