CVE-2026-71297
Description
A flaw was found in the maestro gRPC broker. This vulnerability allows a remote attacker, with a valid client certificate, to bypass authentication. This bypass enables the attacker to subscribe to other consumers' event streams, leading to unauthorized information disclosure, or to publish forged agent status, which can compromise data integrity.
Statement
This vulnerability is rated as Moderate because Maestro is a Technology Preview component within Red Hat Advanced Cluster Management and Multicluster Engine, and the affected gRPC broker backend is not active in default configurations. Exploitation requires environments to explicitly enable the gRPC message broker mode instead of alternative supported backends. Under these non-default configurations, network-adjacent clients can intercept event streams or forge status reports due to missing authorization checks, posing risks to data confidentiality and integrity across participating agents.
Mitigation
To mitigate this issue, ensure that client mTLS is enabled for the Maestro gRPC broker by configuring the `BrokerClientCAFile` parameter. If the gRPC message broker type is not required, avoid enabling it. If the gRPC broker is in use, a restart or service reload may be required after applying the configuration changes.
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 | 5.4 | N/A | 5.4 |
| 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 | Low | N/A | Low |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Understanding the Weakness (CWE)
Access Control,Other
Technical Impact: Gain Privileges or Assume Identity; Varies by Context
Exposing critical functionality essentially provides an attacker with the privilege level of that functionality. The consequences will depend on the associated functionality, but they can range from reading or modifying sensitive data, accessing administrative or other privileged functionality, or possibly even executing arbitrary code.
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