CVE-2026-17107
Cluster-proxy: impersonation-header injection grants cluster-admin on every managed cluster
No known exploitation. EPSS puts it in the 45th percentile. Only a workaround so far.
What to do
No fixed build is published yet. The vendor describes a workaround.
What it is
From the CVE record
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.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.6% chance of exploitation activity in the next 30 days, which ranks it in the 45th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
50 events over 46 days, from the signal feeds we watch.
- Workaround availablerecord updated
- Workaround availablerecord updated
- Workaround availablerecord updated
- Workaround availablerecord updated
- Workaround availablerecord updated
- Workaround availablerecord updated
Affected products
- multicluster engine for Kubernetes 2.1Operating Systems / linux-distro
- multicluster engine for Kubernetes 2.11Cloud & SaaS / container-orchestration
- multicluster engine for Kubernetes 2.17Operating Systems / linux-distro
- multicluster engine for Kubernetes 2.6Cloud & SaaS / container-orchestration
- multicluster engine for Kubernetes 2.8Cloud & SaaS / container-orchestration
- multicluster engine for Kubernetes 2.9Cloud & SaaS / container-orchestration
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Scored 8.5 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity HighRequires specific conditions like a race condition or non-default configuration
- Privileges Required LowRequires basic user-level privileges
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope ChangedThe exploit can affect other components (e.g. sandbox escape, host compromise from VM)
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
Sources
References in the record
- access.redhat.com/errata/RHSA-2026:46885
- access.redhat.com/errata/RHSA-2026:47388
- access.redhat.com/errata/RHSA-2026:47735
And 6 more references. See all after sign-in
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