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Low, CVSS 3.1

Potential proxy IP restriction bypass in Kubernetes

CVE-2020-8562GHSA-qh36-44jv-c8xj

What to do

Vendor response not established. Follow the primary source's mitigation guidance and check back for a fix.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Affected packages

  • Go k8s.io/kubernetes

    Affected
    >= 1.21.0, <= 1.21.1>= 1.20.0, <= 1.20.7>= 1.19.0, <= 1.19.11<= 1.18.19
    Fixed in
    no fixed version recorded

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS
3.1 · CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS
  • CVE-2020-8562: 1.19% estimated exploitation activity in the next 30 days; percentile 67.91 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

As mitigations to a report from 2019 and CVE-2020-8555, Kubernetes attempts to prevent proxied connections from accessing link-local or localhost networks when making user-driven connections to Services, Pods, Nodes, or StorageClass service providers. As part of this mitigation Kubernetes does a DNS name resolution check and validates that response IPs are not in the link-local (169.254.0.0/16) or localhost (127.0.0.0/8) range. Kubernetes then performs a second DNS resolution without validation for the actual connection. If a non-standard DNS server returns different non-cached responses, a user may be able to bypass the proxy IP restriction and access private networks on the control plane. All versions of Kubernetes are impacted, and there is no fix in place.

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 1 · created ·

    Published from ghsa record GHSA-qh36-44jv-c8xj

Agent brief

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# Patch Next advisory brief: CVE-2020-8562

Advisory: Potential proxy IP restriction bypass in Kubernetes
IDs: CVE-2020-8562, GHSA-qh36-44jv-c8xj
Record: https://patchnext.com/advisories/cve-2020-8562 (revision 1, source checked 26 Oct 2026, 15:23 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 3.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go k8s.io/kubernetes: affected >= 1.21.0, <= 1.21.1; >= 1.20.0, <= 1.20.7; >= 1.19.0, <= 1.19.11; <= 1.18.19

## Suggested inspection (read-only)
- Go k8s.io/kubernetes: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on k8s.io/kubernetes.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-qh36-44jv-c8xj (GitHub-reviewed advisory GHSA-qh36-44jv-c8xj lists affected ranges: Go k8s.io/kubernetes >=1.21.0 =1.20.0 =1.19.0 =0 <=1.18.19)

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