CVE-2026-66799
Description
A flaw was found in the cluster-backup-operator. A privileged user with administrative access to a specific namespace could exploit a vulnerability in the backup restoration process. This flaw allows them to redirect sensitive information, such as cloud provider credentials and access tokens, from backup operations into other namespaces, including those they control. This could lead to unauthorized access to critical system resources and the disclosure of confidential data.
Statement
This is an Important vulnerability in Red Hat Advanced Cluster Management for Kubernetes. A namespace administrator within the open-cluster-management-backup namespace can exploit the cluster-backup-operator to redirect sensitive credential Secrets and ConfigMaps from backed-up namespaces into any target namespace, including those controlled by the attacker. This allows for a cross-namespace write of credential material, potentially leading to unauthorized access to cloud provider credentials, pull secrets, and ManagedServiceAccount tokens.
Mitigation
To mitigate this issue, restrict administrative access to the `open-cluster-management-backup` namespace. Only trusted administrators should have permissions to create or modify `Restore` Custom Resources within this namespace, as this action is required to exploit the vulnerability.
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 | 7.1 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | Low | N/A | N/A |
| Integrity Impact | High | N/A | N/A |
| Availability Impact | None | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
Red Hat CVSS v3 Score Explanation
S:U — operator already operates cross-namespace by design. C:L — attacker gets copies of backed-up credential types (cloud creds, MSA tokens), not arbitrary data. I:H — overwrites resources in arbitrary target namespaces.
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Files or Directories
An attacker could bypass intended access restrictions to read sensitive data, either by reading the data directly from a data store that is not correctly 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 bypass intended access restrictions to modify sensitive data, either by writing the data directly to a data store that is not correctly 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 bypass intended access restrictions to gain privileges by modifying or reading critical data directly, or by accessing privileged functionality.
Confidentiality,Integrity,Availability
Technical Impact: Execute Unauthorized Code or Commands
An attacker could use elevated privileges to execute unauthorized commands or code.
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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