CVE-2026-73269
Description
A flaw was found in the cluster-curator-controller component. A local user, by creating a ClusterCurator resource with a specific naming convention, can trigger the creation of a cluster-scoped ClusterRoleBinding. This allows the user to escalate their privileges from namespace-local access to cluster-wide control. This privilege escalation grants broad permissions, including the ability to access and manipulate secrets, manage cluster actions, and delete hosted clusters or node pools.
Statement
This Critical flaw in the Multicluster Engine's cluster-curator-controller allows a tenant with namespace-local access to escalate privileges to cluster-wide. By creating a ClusterCurator resource with a mismatched name and namespace, an attacker can gain extensive permissions, including the ability to manage secrets and delete managed clusters, bypassing existing admission controls. This poses a significant risk to the overall cluster security and data integrity within Red Hat OpenShift environments deploying MCE.
Mitigation
To mitigate this issue, restrict the ability of tenants to create `ClusterCurator` resources. Implement Kubernetes Role-Based Access Control (RBAC) policies to limit `create` permissions for `clustercurators.cluster.open-cluster-management.io` resources to only trusted administrators or service accounts. Alternatively, deploy an admission controller to enforce that `metadata.name` and `metadata.namespace` fields are identical when `ClusterCurator` resources are created, preventing the vulnerable condition.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 9.9 | N/A | 9.9 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Changed | N/A | Changed |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Understanding the Weakness (CWE)
Access Control
Technical Impact: Gain Privileges or Assume Identity
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