Critical [CVE-2026-66795] CSR auto-approver does not validate certificate Subject, signerName, or requester identity
This critical-severity Red Hat Linux advisory covers CVE-2026-66795 affecting Multicluster Engine for Kubernetes.
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Summary
A flaw was found in the managedcluster-import-controller. The Certificate Signing Request (CSR) auto-approval logic improperly validates incoming CSRs, specifically by not inspecting the signer name or decoding the PEM-encoded x509 CSR.
This vulnerability allows a privileged service account on a spoke cluster to submit a malicious CSR. Successful exploitation can lead to privilege escalation, enabling the attacker to obtain administrative credentials on the hub cluster.
This poses a significant risk to the overall security of the multicluster environment. Red Hat severity: Important — CVSS 9.1 (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H).
Weakness: CWE-295. Affected Red Hat products: Multicluster Engine for Kubernetes.
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 3 hours 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 3 hours 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 3 hours ago·verify at source
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