apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: restrict-referencegrants
  annotations:
    policies.kyverno.io/title: Deny ReferenceGrant by default
    policies.kyverno.io/category: Gateway API
    policies.kyverno.io/severity: medium
    policies.kyverno.io/description: >-
      ReferenceGrant is default-deny. Add a named PolicyException for reviewed
      cross-namespace backend cases.
spec:
  validationFailureAction: Audit
  background: true
  rules:
    - name: deny-referencegrant
      match:
        any:
          - resources:
              kinds:
                - ReferenceGrant
      validate:
        message: >-
          ReferenceGrant is not allowed by default. Request a named
          PolicyException after review.
        deny:
          conditions:
            any:
              - key: "{{ request.object.kind }}"
                operator: Equals
                value: ReferenceGrant