{"id":"CVE-2026-66794","title":"A flaw was found in the `cluster-proxy-addon` component of Multicluster Engine for Kubernetes","summary":"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…","severity":"critical","cvss":9.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N","cwe":["CWE-918"],"vendor":"Red Hat","product":"multicluster-engine/cluster-proxy-addon-rhel9","affected":["multicluster-engine/cluster-proxy-addon-rhel9 (all versions)","multicluster-engine/cluster-proxy-rhel9 (all versions)","multicluster-engine/cluster-proxy-rhel9 (all versions)","multicluster-engine/cluster-proxy-addon-rhel9 (all versions)","multicluster-engine/cluster-proxy-addon-rhel9 (all versions)","multicluster-engine/cluster-proxy-addon-rhel9 (all versions)"],"published":"2026-08-19","updated":"2026-09-08","sourceUpdated":"2026-09-08T13:17:21.050","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-66794","references":[{"url":"https://access.redhat.com/errata/RHSA-2026:59556","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:59557","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:59558","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:59559","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:59579","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:59593","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/security/cve/CVE-2026-66794","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2507539","label":"secalert@redhat.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-66794.json"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-66794"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66794"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-08-21T19:33:05.335178Z"},"epss":0.00621,"epssPercentile":0.47463,"ingestedAt":"2026-09-05T19:43:55.383Z","patched":["multicluster_engine_for_kubernetes 2.11","multicluster_engine_for_kubernetes 2.17","multicluster_engine_for_kubernetes 2.1","multicluster_engine_for_kubernetes 2.6","multicluster_engine_for_kubernetes 2.8","multicluster_engine_for_kubernetes 2.9"],"slug":"CVE-2026-66794","body":"## Overview\n\nA 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:59556** · Red Hat · fixed in: multicluster engine for Kubernetes 2.11 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59556)\n- **RHSA-2026:59593** · Red Hat · fixed in: multicluster engine for Kubernetes 2.17 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59593)\n- **RHSA-2026:59557** · Red Hat · fixed in: multicluster engine for Kubernetes 2.1 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59557)\n- **RHSA-2026:59579** · Red Hat · fixed in: multicluster engine for Kubernetes 2.6 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59579)\n- **RHSA-2026:59558** · Red Hat · fixed in: multicluster engine for Kubernetes 2.8 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59558)\n- **RHSA-2026:59559** · Red Hat · fixed in: multicluster engine for Kubernetes 2.9 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59559)","depth":"midnight","depthScore":51,"depthScoreParts":{"impact":51.2,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}