CVE-2026-17107 Cluster-proxy: impersonation-header injection grants cluster-admin on every managed cluster
An authenticated user can inject headers to gain cluster-admin privileges on all managed clusters in Red Hat Advanced Cluster Management.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-17107?
CVE-2026-17107 is a high-severity vulnerability in Red Hat multicluster engine for Kubernetes 2.10, published on 24 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A flaw was found in the cluster-proxy service-proxy component used in Red Hat Advanced Cluster Management for Kubernetes (RHACM) and multicluster-engine (MCE). The service-proxy appends impersonation group headers to proxied requests without first removing caller-supplied values, and the spoke ServiceAccount holds unrestricted impersonation permissions. An authenticated hub principal can inject an Impersonate-Group header to escalate to cluster-admin on every managed cluster.
Weakness: CWE-441
Which versions are affected by CVE-2026-17107?
How do I fix CVE-2026-17107?
No fix has been published for CVE-2026-17107 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-17107 being exploited?
There is no known exploitation of CVE-2026-17107 in the wild and no public exploit code.
Sources
Also known as GHSA-vr7g-637m-v9mm.