CVE-2026-122320
Description
A flaw was found in Kyverno. An authenticated user with permission to create namespaced policies can bypass authorization controls by templating target namespace values within clone generation rules. By triggering the background controller to copy resources from restricted namespaces into an attacker-controlled namespace, an attacker can access sensitive configuration data, leading to cross-tenant information disclosure.
Statement
This vulnerability is rated as Important because authenticated tenants with permissions to manage local policies can breach cross-namespace isolation and access sensitive data without cluster-wide privileges. By manipulating dynamic clone specifications in policy definitions, an attacker forces the privileged background controller to duplicate external resources across tenant boundaries. Red Hat OpenShift does not ship or support Kyverno, relying instead on native platform admission controls and role-based access control to enforce multi-tenant separation.
Mitigation
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.
--- CME Mitigation Guidance (2026-11-06) ---
Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.
The highest-value action is to restrict Kyverno namespaced policy clone and cloneList targets so the background controller cannot duplicate cross-namespace resources: upgrade to Kyverno 1.19.2+ (or the corresponding fixed Red Hat builds), which enforce that namespaced policies only permit clone and cloneList namespace values matching the policy's own namespace, closing all 3 injection vectors (templated generate.clone namespace configuration, templated generate.cloneList namespace configuration, annotated trigger resource invocation). Until patched, this is a concern on Kubernetes clusters running Kyverno where users have permissions to create or manage namespaced Policy resources, so restrict and audit RBAC permissions to create or manage namespaced Policy resources and create or annotate triggering resources like ConfigMaps. As a compensating measure, configure Kubernetes API server audit logging to monitor anomalous cross-namespace resource reads and namespaced Policy creation events. These controls limit blast radius and contain exploitation, but they do not fix the underlying missing namespace authorization defect — apply the upstream patch to fully remediate.
Highest-impact CME: CME-711 Admission Controller Policy Enforcement (OPA/Gatekeeper/Kyverno) (high)
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
Access control checks for specific user data or functionality can be bypassed.
Access Control
Technical Impact: Gain Privileges or Assume Identity
Horizontal escalation of privilege is possible (one user can view/modify information of another user).
Access Control
Technical Impact: Gain Privileges or Assume Identity
Vertical escalation of privilege is possible if the user-controlled key is actually a flag that indicates administrator status, allowing the attacker to gain administrative access.
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