CVE-2026-16543

Summary

Kong Operator's embedded Kong Kubernetes Ingress Controller (KIC) allows a user with namespace-scoped Secret creation privileges to cause a cluster-wide ingress configuration denial of service. The embedded KIC collects CA-certificate Secrets across all watched namespaces using a label selector alone, without ingress-class or namespace restrictions. The CA-certificate primary key is derived from a user-supplied field in the Secret. Duplicate CA-certificate IDs cause Kong Gateway to reject the entire configuration document and halting all ingress changes cluster-wide.

Affected Software

VendorProductVersion RangeStatus
2.2.0 < 2.2.3affected
2.1.0 < 2.1.9affected
0 < 2.0.11affected

Weaknesses

  • CWE-862: CWE-862
  • CWE-400: CWE-400

Workarounds

  1. Restrict ControlPlane watch scope: Change spec.watchNamespaces.type from All to Own or a narrowly defined List that covers only namespaces whose users are trusted operators. This prevents the embedded KIC from ingesting Secrets from untrusted namespaces.2. Restrict Secret labeling via RBAC: Use Kubernetes RBAC to prevent untrusted users from creating or modifying Secrets with the labels konghq.com/secret=true and konghq.com/ca-cert=true. Consider using an admission webhook or OPA/Kyverno policy to enforce this label restriction.

  2. Audit existing CA-cert Secrets: Inspect Secrets labeled konghq.com/ca-cert=true across all watched namespaces for unexpected or duplicate data.id values. Remove any that were not provisioned by a trusted operator.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References