CVE-2026-122319
Description
A flaw was found in Kyverno. This vulnerability allows a remote attacker to cause a Denial of Service (DoS) by submitting specially crafted resources evaluated by the In and NotIn operators. Because the policy engine fails to properly validate unexpected data types, processing these inputs triggers an unhandled crash. This failure halts Kyverno's policy engine, disrupting cluster admission control and security policy enforcement.
Statement
This vulnerability is rated as having Important impact because standard cluster tenants can trigger an unhandled runtime panic by submitting malformed object definitions, leading to a broad denial of service across admission webhooks without requiring administrative privileges. While crashing the service halts policy validation and resource ingestion, the defect does not compromise host confidentiality or permit arbitrary command execution. In standard Red Hat OpenShift environments, Kyverno is neither shipped nor enabled by default, as platform governance is handled through native admission controllers and Red Hat Advanced Cluster Management.
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 eliminate unchecked type assertions during In and NotIn operator evaluation across Kyverno policy evaluation routines: upgrade to Kyverno 1.19.2 (or the corresponding fixed Red Hat builds), which safely handle or validate unexpected non-string data types in In and NotIn operator evaluation to prevent unchecked type assertion panics, closing crafted resource definitions yielding non-string or mixed-type arrays in JMESPath evaluation. Until patched, this is a concern on Kubernetes clusters running Kyverno policies that evaluate resources with In or NotIn operators, so restrict and audit who can submit or modify Kubernetes resources evaluated by Kyverno policies using In or NotIn operators, limiting admission webhook exposure to untrusted tenants. As a compensating measure, configure Kubernetes API server audit policies to capture API requests and identify actors submitting crafted resources that target Kyverno admission webhooks. These controls limit blast radius and contain exploitation, but they do not fix the underlying unchecked type assertion defect — apply the upstream patch to fully remediate.
Highest-impact CME: CME-1011 Kubernetes API Server Audit Policy (medium)
Understanding the Weakness (CWE)
Availability,Confidentiality
Technical Impact: DoS: Crash, Exit, or Restart; Read Application Data
An uncaught exception could cause the system to be placed in a state that could lead to a crash, exposure of sensitive information, or other unintended behaviors.
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