Kyverno Authorization Bypass via Template Variable Injection

Kyverno before 1.19.2 contains an authorization bypass vulnerability that allows namespaced tenants to generate any resource kind in any namespace by templating the generate rule's kind and namespace with variables. Attackers can create a Policy and trigger ConfigMap in their own namespace, causing the privileged background-controller to write NetworkPolicies or RoleBindings into victim or kube-system namespaces.

Casky was already ahead

This CVE exploits attack patterns that Casky's 283matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

Kyverno before version 1.19.2 contains a critical authorization bypass vulnerability (CWE-863: Improper Authorization) that allows namespaced tenants to escalate privileges and create arbitrary resources across cluster namespaces. By exploiting variable templating in generate rules, attackers can craft policies that trick Kyverno's privileged background controller into writing sensitive resources like NetworkPolicies and RoleBindings to protected namespaces including kube-system. This vulnerability is particularly dangerous in multi-tenant Kubernetes environments where namespace isolation is a critical security boundary, potentially allowing a low-privileged user to compromise cluster-wide security posture.

Casky's 283 mapped security skills leverage Claude's extended reasoning to detect the attack patterns underlying this vulnerability across two key MITRE ATT&CK tactics: Privilege Escalation (TA0004) and Credential Access (TA0006). Practitioners using Casky would identify suspicious indicators such as: policy resources with variable templates in kind/namespace fields that differ from the policy's own namespace, ConfigMap creation triggers that precede NetworkPolicy or RoleBinding modifications in restricted namespaces, and background-controller service account activity patterns that violate expected RBAC boundaries. The platform's skill correlation would surface the authorization bypass chain—from initial policy creation through cross-namespace resource generation—enabling security teams to detect both exploitation attempts and misconfigurations before attackers can abuse them.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

283 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-124441.

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

Access with Stolen Session Cookie

identity access management · low

Run

MITRE ATT&CK Techniques

TA0004 TA0006

Investigate the attack patterns behind CVE-2026-124441

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