CVE-2026-66794
Auth bypass in Multicluster Engine proxy allows unauthorized cross-cluster service access
Is CVE-2026-66794 being exploited?
Not confirmed. CVE-2026-66794 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.41% probability of exploitation in the next 30 days.
How severe is CVE-2026-66794?
CVE-2026-66794 is rated Critical with a CVSS score of 9.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-66794?
Yes. A fix has been recorded for CVE-2026-66794. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-66794 affect?
CVE-2026-66794 affects Multicluster Engine for Kubernetes, cluster-proxy-addon, Managed Kubernetes clusters, User-facing proxy routes. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-66794?
Restrict access to user-facing proxy routes, apply vendor patch ASAP, and add WAF/ACLs.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated attacker can proxy arbitrary requests across managed clusters via path manipulation, exposing internal services and enabling data theft or cluster compromise.
Immediate action required