CVE-2020-8561

What it is

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.

At a glance

Exploitability

Can be exploited over the network with an admin-level account. Limited direct impact.

Exploit odds

2.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-09-20 17:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 03:26 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 2.1% in the next 30 days (EPSS).
• Severity: 4.1 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-09-20 17:15 UTC

Last modified

2026-06-17 03:26 UTC

Exploit probability

2.1% · EPSS, next 30 days

Weakness

CWE-441

Record status

Modified

Affected

• Kubernetes 1.20.11
• Kubernetes 1.21.5
• Kubernetes 1.22.2

Attack profile CVSS 3.1 · 4.1

Attack vector

Network

Complexity

Low

Privileges needed

High

User interaction

None

Scope

Changed

Confidentiality

Low

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2020-8561.md and follow it. Check whether this project is affected by CVE-2020-8561. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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