Vulnerability · Published Aug 19, 2026 · Assigned by redhat
CVE-2026-66794Cluster-proxy-addon: cluster-proxy-addon: unauthenticated ssrf to arbitrary managed-cluster services via public route
Critical 9.3
In plain English
A critical-severity server-side request forgery in multicluster engine for Kubernetes 2.10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities).
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | multicluster engine for Kubernetes 2.10 | see references |
| Red Hat | multicluster engine for Kubernetes 2.11 | see references |
| Red Hat | multicluster engine for Kubernetes 2.17 | see references |
| Red Hat | multicluster engine for Kubernetes 2.6 | see references |
| Red Hat | multicluster engine for Kubernetes 2.8 | see references |
| Red Hat | multicluster engine for Kubernetes 2.9 | see references |
Weakness: CWE-918 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
References
- RHSA-2026:59556 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:59557 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:59558 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:59559 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:59579 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:59593 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-66794 vdb-entry, x_refsource_REDHAT
- RHBZ#2507539 issue-tracking, x_refsource_REDHAT