High [CVE-2026-66878] FetchChannelReferences honours Channel.spec.secretRef.namespace enabling cross-namespace Secret exfiltration
This high-severity Red Hat Linux advisory covers CVE-2026-66878 affecting Red Hat Advanced Cluster Management for Kubernetes 2.
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Summary
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.
This Important flaw in Red Hat Advanced Cluster Management allows a malicious namespace administrator to exfiltrate sensitive Secret data from other namespaces within the cluster. This impacts environments where untrusted namespace administrators have permissions to create Channel and Subscription resources.
Red Hat severity: Important — CVSS 7.7 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N). Weakness: CWE-639.
Affected Red Hat products: Red Hat Advanced Cluster Management for Kubernetes 2. Red Hat does not currently list a fixing RHSA for this CVE.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · high-confidence parse· fetched 1 hour ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · high-confidence parse· fetched 1 hour ago·verify at source
Mitigation checklist
- 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.
Official advisory · high-confidence parse· fetched 1 hour ago·verify at source
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