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Vulnerability record · CVE-2026-66795 · published 17 August 2026

CVE-2026-66795: Improper certificate validation vulnerability

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.

9.9 CVSS 3.1 Critical EPSS 0.49% · top 60.4% CWE-295 · Improper certificate validation Awaiting Analysis
9.9CVSS 3.1 base score
0.49%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
8References
8 Sep 2026Last modified by NVD

Description

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.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

References

LinkTags
https://access.redhat.com/errata/RHSA-2026:59556
https://access.redhat.com/errata/RHSA-2026:59557
https://access.redhat.com/errata/RHSA-2026:59558
https://access.redhat.com/errata/RHSA-2026:59559
https://access.redhat.com/errata/RHSA-2026:59579
https://access.redhat.com/errata/RHSA-2026:59593
https://access.redhat.com/security/cve/CVE-2026-66795
https://bugzilla.redhat.com/show_bug.cgi?id=2507540

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Source: NIST National Vulnerability Database (record CVE-2026-66795), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.