How severe is CVE-2020-8555?

CVE-2020-8555 has a CVSS score of 6.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2020-8555?

CVE-2020-8555 affects the following packages: k8s.io/kubernetes (Go), k8s.io/kubernetes (Go), k8s.io/kubernetes (Go), k8s.io/kubernetes (Go). Ecosystems affected: Go.

How do I fix CVE-2020-8555?

Update k8s.io/kubernetes to 1.18.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-8555 is resolved across your whole dependency graph.

How do I detect CVE-2020-8555 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for k8s.io/kubernetes, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2020-8555 if there is no patch (or I can't update yet)?

Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Is CVE-2020-8555 actively exploited in the wild?

No public exploit code has been indexed for CVE-2020-8555 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2020-8555?

CVE-2020-8555 has an EPSS (Exploit Prediction Scoring System) score of 3.7%, placing it in the 89th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2020-8555?

CVE-2020-8555 is classified as Server-Side Request Forgery (SSRF) (CWE-918). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2020-8555 published, and has it been updated?

CVE-2020-8555 was published on June 5, 2020 and was last updated on August 7, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

MEDIUM severity

CVE-2020-8555 — kubernetes

MEDIUMFix: kubernetes/kubernetes#89794

CVE-2020-8555 is a medium-severity (CVSS 6.3) Server-Side Request Forgery (SSRF) vulnerability in k8s.io/kubernetes. A fix is available for k8s.io/kubernetes — see the affected versions and patch details below.

Server Side Request Forgery (SSRF) in Kubernetes

Also known asGHSA-x6mj-w4jf-jmgwGO-2022-0890

Published

Jun 5, 2020

Updated

Aug 7, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Exploitation data as of Oct 9, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

3.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs89th percentile — riskier than 89% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2020-8555 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

4 pkgs affected

🐹k8s.io/kubernetes🐹k8s.io/kubernetes🐹k8s.io/kubernetes🐹k8s.io/kubernetes

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

The Kubernetes kube-controller-manager in versions v1.0-1.14, versions prior to v1.15.12, v1.16.9, v1.17.5, and version v1.18.0 are vulnerable to a Server Side Request Forgery (SSRF) that allows certain authorized users to leak up to 500 bytes of arbitrary information from unprotected endpoints within the master's host network (such as link-local or loopback services).

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`k8s.io/kubernetes`	≥ 1.18.0&&< 1.18.1	1.18.1`go get k8s.io/kubernetes@v1.18.1`
🐹Go	`k8s.io/kubernetes`	≥ 1.17.0&&< 1.17.4	1.17.4`go get k8s.io/kubernetes@v1.17.4`
🐹Go	`k8s.io/kubernetes`	≥ 1.16.0&&< 1.16.9	1.16.9`go get k8s.io/kubernetes@v1.16.9`
🐹Go	`k8s.io/kubernetes`	all versions	1.15.12`go get k8s.io/kubernetes@v1.15.12`

Affected Products

2 products · 5 configurations

fedorafedoraproject

1 version

Application

kuberneteskubernetes

≥ 1.17.0 && < 1.17.5

1 version

1.18.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for k8s.io/kubernetes, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update k8s.io/kubernetes to 1.18.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-8555 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

OpenShift Container Platform does not expose kube-apiserver through an unauthenticated localhost port. However, other link-local addresses are reachable without authentication that allow an attacker to access sensitive data. The version of heketi shipped with Red Hat Gluster Storage 3 includes the affected client side…

Workaround published by Red Hat

Restrict use of the vulnerable volume type and restrict StorageClass write permissions via RBAC

Source: Red Hat security advisory for CVE-2020-8555 (CC BY 4.0)

Product	Fixed in	Advisory
Red Hat OpenShift Container Platform 3.11	`atomic-openshift-0:3.11.232-1.git.0.a5bc32f.el7`	RHSA-2020:2479
Red Hat OpenShift Container Platform 4.2	`openshift-0:4.2.36-202006211650.p0.git.0.1fe246f.el7`	RHSA-2020:2594
Red Hat OpenShift Container Platform 4.3	`openshift-0:4.3.25-202006060952.git.1.96c30f6.el8`	RHSA-2020:2440
Red Hat OpenShift Container Platform 4.3	`openshift4/ose-hyperkube:v4.3.25-202006081335`	RHSA-2020:2441
Red Hat OpenShift Container Platform 4.4	`openshift-0:4.4.0-202006061254.git.1.dc84fb4.el8`	RHSA-2020:2448
Red Hat OpenShift Container Platform 4.4	`openshift4/ose-hyperkube:v4.4.0-202006080610`	RHSA-2020:2449

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2020-8555 in your dependencies?

Find it across Go, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

6.3/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

None

Availability

None

Raw vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

CWE Classification

CWE-918Server-Side Request Forgery (SSRF)

Weaponization

No known public exploit tooling found.

OpenSSF Scorecard

Package health score

kubernetes

7.6/10

Code-Review10/10

Maintained10/10

Branch-ProtectionN/A

Assessed Oct 5, 2026

Timeline

Disclosed

Jun 5, 2020

Last updated

Aug 7, 2026

Identifiers

CVE-2020-8555

GHSA-x6mj-w4jf-jmgw

GO-2022-0890

References

Advisoryopenwall.com Advisoryopenwall.com Advisorygithub.com Advisorygroups.google.com Advisorysecurity.netapp.com Advisorynvd.nist.gov Weblists.fedoraproject.org Webgithub.com Weblists.fedoraproject.org Websecurity.netapp.com

Related vulnerabilities

This CVE is medium severity; 7 of 8 other CVEs affecting kubernetes are rated as high or higher (top: high).

CVE-2025-13281CVE-2025-5187CVE-2025-4563CVE-2025-1767CVE-2024-9042CVE-2025-0426CVE-2024-10220CVE-2024-0793

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedAug 7, 2026

CVE-2020-8555 — kubernetes

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Fixing This On Your OS

Frequently Asked Questions

Is CVE-2020-8555 in your dependencies?