CVE-2026-17107
An authenticated hub principal can inject an Impersonate-Group header to escalate to cluster-admin on every managed cluster.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.57%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 8.5 HIGHCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 0.57% probability · 47th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-441
- Source
- secalert@redhat.com
EPSS 0.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://access.redhat.com/errata/RHSA-2026:46885
- https://access.redhat.com/errata/RHSA-2026:47388
- https://access.redhat.com/errata/RHSA-2026:47735
- https://access.redhat.com/errata/RHSA-2026:47949
- https://access.redhat.com/errata/RHSA-2026:47953
- https://access.redhat.com/errata/RHSA-2026:47974
- https://access.redhat.com/errata/RHSA-2026:48284
- https://access.redhat.com/security/cve/CVE-2026-17107
- https://bugzilla.redhat.com/show_bug.cgi?id=2506771
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.