CVE-2026-66800
Description
A flaw was found in cluster-backup-operator. A namespace administrator with privileges in the open-cluster-management-backup namespace can exploit a feature in the Restore Custom Resource (CR). By setting the cleanupBeforeRestore field to CleanupAll, an attacker can trigger an unguarded, cluster-wide deletion of all Red Hat Advanced Cluster Management (ACM) and Hive-labelled Secrets and ConfigMaps. This leads to a denial of service across the entire hub cluster by removing critical resources.
Statement
This vulnerability is rated as Important. A namespace administrator within the open-cluster-management-backup namespace in Red Hat Advanced Cluster Management for Kubernetes can initiate a cluster-wide denial of service. This occurs by leveraging the cleanupBeforeRestore: CleanupAll option in a Restore Custom Resource, which causes the cluster-backup-operator to delete all ACM/Hive-labelled Secrets and ConfigMaps across the hub cluster, regardless of their restore labels.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.1 | 7.5 | 8.6 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Changed |
| Confidentiality | None | High | High |
| Integrity Impact | Low | None | None |
| Availability Impact | High | None | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N/E:U/RL:O/RC:C
Red Hat CVSS v3 Score Explanation
C:N — deletion does not expose data. I:L — deleted resources recoverable from backup. A:H — cluster-wide deletion of ACM/Hive-labelled Secrets, ConfigMaps, and dynamic resources.
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Files or Directories
An attacker could read sensitive data, either by reading the data directly from a data store that is not restricted, or by accessing insufficiently-protected, privileged functionality to read the data.
Integrity
Technical Impact: Modify Application Data; Modify Files or Directories
An attacker could modify sensitive data, either by writing the data directly to a data store that is not restricted, or by accessing insufficiently-protected, privileged functionality to write the data.
Access Control
Technical Impact: Gain Privileges or Assume Identity; Bypass Protection Mechanism
An attacker could gain privileges by modifying or reading critical data directly, or by accessing privileged functionality.
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
An attacker could gain unauthorized access to resources on the system and excessively consume those resources, leading to a denial of service.
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