CVE-2026-66780
Description
A flaw was found in the submariner-operator component. The submariner-k8s-broker-cluster Role, which is assigned to joined clusters, possesses excessive permissions. This allows a compromised cluster to alter network configurations, specifically by overwriting other clusters' endpoint information. Consequently, an attacker can redirect inter-cluster tunnel traffic, enabling a Man-in-the-Middle (MITM) attack across the entire cluster mesh.
Statement
Critical: Red Hat Advanced Cluster Management for Kubernetes is vulnerable to a critical flaw in the submariner-operator where a compromised spoke cluster can achieve a Man-in-the-Middle (MITM) attack across the entire cluster mesh. This is due to the submariner-k8s-broker-cluster Role granting overly broad permissions, allowing any joined cluster to modify endpoint configurations for all other clusters within the broker namespace. This broad access enables an attacker to redirect inter-cluster tunnel traffic.
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 | 6.5 | N/A | 6.5 |
| 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 | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Red Hat CVSS v3 Score Explanation
Reconciled from source finding FIND-001 (migration 2026-09-01)
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Logging sensitive user data, full path names, or system information often provides attackers with an additional, less-protected path to acquiring the information.
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