CVE-2026-66794 Cluster-proxy-addon: cluster-proxy-addon: unauthenticated ssrf to arbitrary managed-cluster services via public route
Unauthenticated attackers can bypass authentication to access arbitrary internal services across managed clusters via the cluster-proxy-addon route.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-66794?
CVE-2026-66794 is a critical server-side request forgery vulnerability in Red Hat multicluster engine for Kubernetes 2.10, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-918
Which versions are affected by CVE-2026-66794?
How do I fix CVE-2026-66794?
No fix has been published for CVE-2026-66794 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-66794 being exploited?
There is no known exploitation of CVE-2026-66794 in the wild and no public exploit code.
Sources
Also known as GHSA-9855-9cch-x8mw.