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Upstream Ingress-Nginx CVEs - CVE-2025-15566, CVE-2026-1580, CVE-2026-24512, CVE-2026-24513, and CVE-2026-24514

· 2 min read
Ivan Sim

This article provides information and mitigation steps for the following vulnerabilities in Harvester:

important

These vulnerabilities affect specific versions of the RKE2 ingress-nginx controller (v1.13.7 and earlier, v1.14.3 and earlier). All Harvester versions that use this controller (including 1.5.2 and earlier, 1.6.1 and earlier, and 1.7.0) are therefore affected.

These CVEs are fixed in Harvester 1.7.1 and newer.

important

Harvester does not utilize the ingress-nginx controller custom error backend. Therefore, it is not affected by CVE-2026-24513.

important

Currently, no mitigation is available for CVE-2026-24514. An upgrade to Harvester 1.7.1 is required.

For more information on its CVSS score, see https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

You can confirm the version of the RKE2 ingress-nginx pods by running this command on your Harvester cluster:

kubectl -n kube-system get po -l"app.kubernetes.io/name=rke2-ingress-nginx" -ojsonpath='{.items[].spec.containers[].image}'

If the command returns one of the affected versions, perform one of the following mitigation steps.

The primary resolution is to upgrade to Harvester 1.7.1 or newer, which includes the fixed RKE2 ingress-nginx controller.

If upgrade is not possible, deploy the following validating admission policy to your cluster to reject ingress resources with the vulnerable configuration:

cat<<EOF | kubectl apply -f -
apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingAdmissionPolicy
metadata:
  name: ingress-nginx-annotation-validation
spec:
  failurePolicy: Fail
  matchConstraints:
    resourceRules:
    - apiGroups:   ["networking.k8s.io"]
      apiVersions: ["v1"]
      operations:  ["CREATE", "UPDATE"]
      resources:   ["ingresses"]
  validations:
    - expression: |
        !('nginx.ingress.kubernetes.io/auth-proxy-set-headers' in object.metadata.annotations) &&
        !('nginx.ingress.kubernetes.io/auth-method' in object.metadata.annotations) &&
        (object.spec.rules.all(rule, rule.http.paths.all(path, path.pathType != 'ImplementationSpecific')))
      message: "Ingress resources with the vulnerable annotations are not allowed. Please remove the 'nginx.ingress.kubernetes.io/auth-proxy-set-headers' and 'nginx.ingress.kubernetes.io/auth-method' annotations, and avoid using the 'ImplementationSpecific' path type."
---
apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingAdmissionPolicyBinding
metadata:
  name: ingress-nginx-annotation-validation
spec:
  policyName: ingress-nginx-annotation-validation
  validationActions: [Deny]
EOF
info

This policy is a cluster-scoped resource that requires the proper administrator RBAC permissions to create.

This validating policy rejects any ingress resources that contain the:

  • nginx.ingress.kubernetes.io/auth-proxy-set-headers annotation
  • nginx.ingress.kubernetes.io/auth-method annotation
  • ImplementationSpecific path type

The policy can be removed once you upgrade to Harvester 1.7.1 or newer:

kubectl delete validatingadmissionpolicy ingress-nginx-annotation-validation

kubectl delete validatingadmissionpolicybinding ingress-nginx-annotation-validation

References​