CVE-2020-8561
MEDIUMEPSS 80th pctlDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N
Exploit Intelligence
Elevated risk: more likely to be exploited than 80% of all known CVEs.
References
Related Vulnerabilities
Other CWE-441 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2025-47269 | High | 8.3 | 43% | - | - |
| CVE-2019-3924 | High | 7.5 | 16% | - | Fix |
| CVE-2020-5412 | Medium | 6.5 | 10% | - | Fix |
| CVE-2019-3996 | Medium | 6.5 | 5.9% | - | - |
| CVE-2021-20042 | Critical | 9.8 | 2.7% | - | - |
| CVE-2019-1841 | Medium | 6.5 | 2.6% | - | Fix |
Common questions
How do I fix CVE-2020-8561?
Upgrade kubernetes on debian 11 to 1.20.5+really1.20.2-1 or later.
Is CVE-2020-8561 being actively exploited?
Not that we know of. CVE-2020-8561 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 2.1% is the estimated probability that it will be exploited in the next 30 days. That is higher than 80% of all scored CVEs.
How severe is CVE-2020-8561?
CVE-2020-8561 has a CVSS v3 base score of 4.1, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2020-8561 affect?
Published advisories record a fix for kubernetes (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-01.