---
id: CVE-2026-66795
title: A flaw was found in the managedcluster-import-controller
summary: >-
  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. …
severity: critical
cvss: 9.9
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-295
vendor: Red Hat
product: multicluster-engine/managedcluster-import-controller-rhel9
affected:
  - multicluster-engine/managedcluster-import-controller-rhel9 (all versions)
  - multicluster-engine/managedcluster-import-controller-rhel9 (all versions)
  - multicluster-engine/managedcluster-import-controller-rhel9 (all versions)
  - multicluster-engine/managedcluster-import-controller-rhel9 (all versions)
  - multicluster-engine/managedcluster-import-controller-rhel9 (all versions)
  - multicluster-engine/managedcluster-import-controller-rhel9 (all versions)
published: '2026-08-17'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T13:17:21.200'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-66795'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:59556'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:59557'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:59558'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:59559'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:59579'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:59593'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-66795'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2507540'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-66795.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-66795'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-66795'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-08-18T15:15:25.705433Z'
epss: 0.00488
epssPercentile: 0.39386
ingestedAt: '2026-09-05T18:43:14.578Z'
patched:
  - multicluster_engine_for_kubernetes 2.11
  - multicluster_engine_for_kubernetes 2.17
  - multicluster_engine_for_kubernetes 2.1
  - multicluster_engine_for_kubernetes 2.6
  - multicluster_engine_for_kubernetes 2.8
  - multicluster_engine_for_kubernetes 2.9
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **RHSA-2026:59556** · Red Hat · fixed in: multicluster engine for Kubernetes 2.11 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59556)
- **RHSA-2026:59593** · Red Hat · fixed in: multicluster engine for Kubernetes 2.17 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59593)
- **RHSA-2026:59557** · Red Hat · fixed in: multicluster engine for Kubernetes 2.1 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59557)
- **RHSA-2026:59579** · Red Hat · fixed in: multicluster engine for Kubernetes 2.6 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59579)
- **RHSA-2026:59558** · Red Hat · fixed in: multicluster engine for Kubernetes 2.8 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59558)
- **RHSA-2026:59559** · Red Hat · fixed in: multicluster engine for Kubernetes 2.9 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59559)