CVE-2026-66878: Multicloud-operators-subscription: multicloud-operators-subscription: fetchchannelreferences honours channel.spec.secretref.namespace enabling cross-namespace secret exfiltration

Severity: high (CVSS 7.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-12 · updated 2026-10-24
Weakness: CWE-639

Description

A flaw was found in multicloud-operators-subscription. A privileged user, specifically a namespace administrator capable of creating Channel and Subscription resources, can exploit this vulnerability. By manipulating the Channel.Spec.SecretRef.Namespace field, the user can cause the system to copy sensitive Secret contents from other namespaces into their own, leading to information disclosure.

Affected products

Red Hat Advanced Cluster Management for Kubernetes 2.11: all versions — fixed in 1787263584
Red Hat Advanced Cluster Management for Kubernetes 2.13: all versions — fixed in 1787263693
Red Hat Advanced Cluster Management for Kubernetes 2.14: all versions — fixed in 1787170830
Red Hat Advanced Cluster Management for Kubernetes 2.15: all versions — fixed in 1787240030
Red Hat Advanced Cluster Management for Kubernetes 2.16: all versions — fixed in 1787242321
Red Hat Advanced Cluster Management for Kubernetes 2.17: all versions — fixed in 1787242108

How to fix

Upgrade to a fixed version: Red Hat Advanced Cluster Management for Kubernetes 2.11 1787263584; Red Hat Advanced Cluster Management for Kubernetes 2.13 1787263693; Red Hat Advanced Cluster Management for Kubernetes 2.14 1787170830; Red Hat Advanced Cluster Management for Kubernetes 2.15 1787240030; Red Hat Advanced Cluster Management for Kubernetes 2.16 1787242321; Red Hat Advanced Cluster Management for Kubernetes 2.17 1787242108. Check the vendor advisory for mitigations.

References

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