9.3
CRITICAL CVSS 3.1
CVE-2026-66794
Cluster-proxy-addon: cluster-proxy-addon: unauthenticated ssrf to arbitrary managed-cluster services via public route
Description

A flaw was found in the `cluster-proxy-addon` component of Multicluster Engine for Kubernetes. This vulnerability allows an unauthenticated attacker, who can access the user-facing route, to bypass authentication and authorization checks. By manipulating URL path segments, the attacker can proxy requests to arbitrary services across any managed cluster. This enables unauthorized access to internal services that would otherwise be protected, potentially leading to information disclosure or further compromise of the cluster environment.

INFO

Published Date :

Aug. 19, 2026, 6:17 p.m.

Last Modified :

Aug. 19, 2026, 6:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-66794 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Redhat multicluster_engine_for_kubernetes
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL 53f830b8-0a3f-465b-8143-3b8a9948e749
CVSS 3.1 CRITICAL [email protected]
Solution
Update to a patched version to fix authentication bypass and unauthorized access.
  • Update cluster-proxy-addon to a patched version.
  • Restrict access to user-facing routes.
  • Validate all incoming requests for authentication.
  • Enforce proper authorization checks.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-66794.

URL Resource
https://access.redhat.com/security/cve/CVE-2026-66794
https://bugzilla.redhat.com/show_bug.cgi?id=2507539
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-66794 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-66794 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-66794 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-66794 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Aug. 19, 2026

    Action Type Old Value New Value
    Added Affected [{'cpes': ['cpe:/a:redhat:multicluster_engine'], 'vendor': 'Red Hat', 'product': 'Multicluster Engine for Kubernetes', 'packageName': 'multicluster-engine/cluster-proxy-addon-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:multicluster_engine'], 'vendor': 'Red Hat', 'product': 'Multicluster Engine for Kubernetes', 'packageName': 'multicluster-engine/cluster-proxy-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'affected'}]
    Added Description A flaw was found in the `cluster-proxy-addon` component of Multicluster Engine for Kubernetes. This vulnerability allows an unauthenticated attacker, who can access the user-facing route, to bypass authentication and authorization checks. By manipulating URL path segments, the attacker can proxy requests to arbitrary services across any managed cluster. This enables unauthorized access to internal services that would otherwise be protected, potentially leading to information disclosure or further compromise of the cluster environment.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
    Added CWE CWE-918
    Added Reference https://access.redhat.com/security/cve/CVE-2026-66794
    Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2507539
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.