CVE-2026-66795
Managedcluster-import-controller: csr auto-approver does not validate certificate subject or signername (spoke→hub cluster-admin)
CRITICAL 9.9
At a glance
- Source
- NVD
- EPSS
- EPSS 0.49 % · percentile 42 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- redhat
- NVD status
- Awaiting Analysis
Description
A flaw was found in the managedcluster-import-controller. The Certificate Signing Request (CSR) auto-approval logic improperly validates incoming CSRs, specifically by not inspecting the signer name or decoding the PEM-encoded x509 CSR. This vulnerability allows a privileged service account on a spoke cluster to submit a malicious CSR. Successful exploitation can lead to privilege escalation, enabling the attacker to obtain administrative credentials on the hub cluster.
Weaknesses (CWE)
- CWE-295 — Improper Certificate Validation
References
- https://access.redhat.com/errata/RHSA-2026:59556
- https://access.redhat.com/errata/RHSA-2026:59557
- https://access.redhat.com/errata/RHSA-2026:59558
- https://access.redhat.com/errata/RHSA-2026:59559
- https://access.redhat.com/errata/RHSA-2026:59579
- https://access.redhat.com/errata/RHSA-2026:59593
- https://access.redhat.com/security/cve/CVE-2026-66795
- https://bugzilla.redhat.com/show_bug.cgi?id=2507540
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | CRITICAL 9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H | redhat |
| CVSS 3.1 | CRITICAL 9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H | NVD · secalert@redhat.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-60452
- GCVE · GCVE-0-2026-66795
Affected products
| Product | Versions |
|---|---|
| Red Hat · multicluster engine for Kubernetes 2.10 | unaffected 1787078272 < * |
| Red Hat · multicluster engine for Kubernetes 2.11 | unaffected 1787078330 < * |
| Red Hat · multicluster engine for Kubernetes 2.17 | unaffected 1786577915 < * |
| Red Hat · multicluster engine for Kubernetes 2.6 | unaffected 1787260779 < * |
| Red Hat · multicluster engine for Kubernetes 2.8 | unaffected 1787259044 < * |
| Red Hat · multicluster engine for Kubernetes 2.9 | unaffected 1787078307 < * |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |