CVE-2020-8561

A security issue was discovered in Kubernetes where actors that control the responses of MutatingWebhookConfiguration or ValidatingWebhookConfiguration requests are able to redirect kube-apiserver requests to private networks of the apiserver. If that user can view kube-apiserver logs when the log level is set to 10, they can view the redirected responses and headers in the logs.

• CWE-441
• CWE-610

• https://github.com/kubernetes/kubernetes/issues/104720Mitigation, Third Party Advisory
• https://groups.google.com/g/kubernetes-security-announce/c/RV2IhwcrQsYMailing List, Mitigation
• https://kubernetes.io/blog/2026/05/26/reconciling-unfixed-kubernetes-cves/
• https://security.netapp.com/advisory/ntap-20211014-0002/Third Party Advisory
• https://github.com/kubernetes/kubernetes/issues/104720Mitigation, Third Party Advisory
• https://groups.google.com/g/kubernetes-security-announce/c/RV2IhwcrQsYMailing List, Mitigation
• https://security.netapp.com/advisory/ntap-20211014-0002/Third Party Advisory

Published

Sep 20, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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• CVE-2020-8553The Kubernetes ingress-nginx component prior to version 0.28…5.9
• CVE-2020-8554Kubernetes API server in all versions allow an attacker who …5
• CVE-2020-8555The Kubernetes kube-controller-manager in versions v1.0-1.14…6.3
• CVE-2020-8557The Kubernetes kubelet component in versions 1.1-1.16.12, 1.…5.5
• CVE-2020-8558The Kubelet and kube-proxy components in versions 1.1.0-1.16…8.8
• CVE-2020-8559The Kubernetes kube-apiserver in versions v1.6-v1.15, and ve…6.8
• CVE-2020-8562As mitigations to a report from 2019 and CVE-2020-8555, Kube…3.1
• CVE-2020-8563In Kubernetes clusters using VSphere as a cloud provider, wi…5.5
• CVE-2020-8564In Kubernetes clusters using a logging level of at least 4, …5.5
• CVE-2020-8565In Kubernetes, if the logging level is set to at least 9, au…5.5
• CVE-2020-8566In Kubernetes clusters using Ceph RBD as a storage provision…5.5
• CVE-2020-8567Kubernetes Secrets Store CSI Driver Vault Plugin prior to v0…6.5