CVE-2026-66801

critical Red Hat
CVSS v3 Base Score
9.9
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Published: August 10, 2026 (27 days ago)
Last Modified: August 10, 2026
Vendor: Red Hat
Fix Available: ✓ Yes
Source: REDHAT

Description

A flaw was found in multicluster-global-hub. An attacker who compromises a managed hub can leverage its legitimate Kafka client certificate to publish a CloudEvent (a specification for describing event data in a common way) message to the shared `gh-spec` topic. This message can spoof its source as "global-hub" and target other managed hubs. Due to a lack of binding between the Kafka client principal and the CloudEvent envelope, the agent on the targeted hub accepts this spoofed message and applies arbitrary resources. This vulnerability allows for fleet-wide cluster-admin privilege escalation across all managed hubs.

CWE

CWE-290

Affected Products

Multicluster Global Hub 1.8.1

Fix Status

✅ Fix Available

References

🔗 bugzilla.redhat.com 🔗 www.cve.org 🔗 nvd.nist.gov