Cluster-Proxy-Addon Vulnerability in Multicluster Engine
- Severity
- CRITICAL
- CVSS
- 9.3
- Affected component
- cluster-proxy-addon (npm)
- Patched version
- Not yet available
A critical vulnerability has been reported in the cluster-proxy-addon component of Multicluster Engine for Kubernetes. This flaw may enable unauthenticated attackers to bypass security checks, potentially leading to unauthorized access and information disclosure.
What happened
An unauthenticated attacker may exploit a flaw in the cluster-proxy-addon component to bypass authentication and authorization checks. This could allow the attacker to proxy requests to arbitrary services across any managed cluster, leading to unauthorized access to internal services and potential information disclosure.
The vulnerability was first flagged on August 19, 2026. The National Vulnerability Database (NVD) has assigned it the identifier CVE-2026-66794 with a CVSS score of 9.3, indicating a critical severity level. The specific version range affected by this vulnerability has not yet been published.
What to do about it
- Upgrade to the latest version of cluster-proxy-addon as soon as it becomes available.
- Review and strengthen access controls for all user-facing routes in your cluster environment.
- Monitor the NVD and other primary sources for updates on the vulnerability and any official fixes.
- Consider implementing additional security measures to protect against potential unauthorized access.
- No official fix has been published yet. Monitor the sources below for updates.
How 0Day would have caught this
cluster-proxy-addon is anywhere in your dependency tree, the engineers who own the affected repositories get a push alert the moment it is flagged — no manual audit to remember to run.Read how this differs from waiting on a scanner to catch a known advisory, or see the exact, read-only access 0Day needs to do this for an organization.
Frequently asked questions
Am I affected?
If your system uses the cluster-proxy-addon component of Multicluster Engine for Kubernetes, you may be affected. The specific version range has not yet been published.
What should I do right now?
Upgrade to the latest version of cluster-proxy-addon as soon as it becomes available and review your access controls.
Has this been exploited in the wild?
There is no evidence that this vulnerability has been exploited in the wild at this time.