Cluster-proxy-addon: cluster-proxy-addon: unauthenticated ssrf to arbitrary managed-cluster services via public route
Summary
| CVE | CVE-2026-66794 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-19 18:17:16 UTC |
| Updated | 2026-09-08 13:17:21 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 9.3 CRITICAL from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
EPSS: 0.004100000 probability, percentile 0.342160000 (date 2026-09-07)
Problem Types: CWE-918 | CWE-918 Server-Side Request Forgery (SSRF)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 9.3 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N |
| 3.1 | CNA | CVSS | 9.3 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
ChangedConfidentiality
HighIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Multicluster Engine For Kubernetes 2.1 | unaffected 1787173361 * rpm | Not specified |
| CNA | Red Hat | Multicluster Engine For Kubernetes 2.11 | unaffected 1787276784 * rpm | Not specified |
| CNA | Red Hat | Multicluster Engine For Kubernetes 2.17 | unaffected 1786983349 * rpm | Not specified |
| CNA | Red Hat | Multicluster Engine For Kubernetes 2.6 | unaffected 1787275318 * rpm | Not specified |
| CNA | Red Hat | Multicluster Engine For Kubernetes 2.8 | unaffected 1787275519 * rpm | Not specified |
| CNA | Red Hat | Multicluster Engine For Kubernetes 2.9 | unaffected 1787274923 * rpm | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/errata/RHSA-2026:59593 | [email protected] | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:59556 | [email protected] | access.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-66794 | [email protected] | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:59557 | [email protected] | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:59579 | [email protected] | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:59558 | [email protected] | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| access.redhat.com/errata/RHSA-2026:59559 | [email protected] | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-07-27T00:00:00.000Z | Reported to Red Hat. |
| CNA | 2026-08-19T14:00:00.000Z | Made public. |
Workarounds
CNA: To mitigate this issue, restrict network access to the user-facing Route of the `cluster-proxy-addon` to trusted networks only. Implement firewall rules to limit inbound connections to the Route's exposed port, ensuring only authorized sources can reach it. This reduces the attack surface by preventing unauthenticated external access to the vulnerable proxy.
There are currently no legacy QID mappings associated with this CVE.