Bug 2507539 (CVE-2026-66794)

Summary:	CVE-2026-66794 cluster-proxy-addon: cluster-proxy-addon: unauthenticated SSRF to arbitrary managed-cluster services via public Route
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	gparvin, rhaigner, security-response-team
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	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.	Story Points:	---
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Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-07-27 15:45:52 UTC

The user-facing Route uses tls.termination: reencrypt with no client-cert requirement and no oauth-proxy sidecar. The user-server ServeHTTP handler performs no authentication or authorization; it parses the URL and proxies to managed-cluster services. The target host is built from client-controlled URL path segments (Cluster-Proxy-Namespace / Service / Port headers). No allow-list is consulted; the ManagedProxyServiceResolver CRD governs only what the ANP agent may dial and is not enforced for the second hop. An unauthenticated attacker who can reach the Route can proxy requests to arbitrary services on any managed cluster, including internal services not otherwise exposed.

Source: Project Glasswing AI-SAST audit of stolostron/cluster-proxy-addon.
Finding ID: CPA-2026-002
Assurance: machine_verified