SSRF in Red Hat Multicluster Engine For Kubernetes
CVE-2026-66794
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.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.3 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N.
EPSS exploit prediction
EPSS: 0.006 (47.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 48th percentile — 47.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002
Affected products
Weakness classification (CWE)
References
- access.redhat.com/security/cve/CVE-2026-66794 (vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking)
- access.redhat.com/errata/RHSA-2026:59556 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:59593 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:59557 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:59558 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:59559 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:59579 (vendor-advisory)
Frequently asked questions
- What is CVE-2026-66794?
- CVE-2026-66794 is a critical-severity vulnerability in Red Hat Multicluster Engine For Kubernetes, classified under Server-Side Request Forgery (SSRF). CVSS score: 9.3/10. Published 2026-08-19.
- How severe is CVE-2026-66794?
- Critical severity. CVSS v3 base score is 9.3 out of 10.