How severe is CVE-2021-20218?

CVE-2021-20218 has a CVSS score of 7.4/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-20218?

CVE-2021-20218 affects the following packages: io.fabric8:kubernetes-client (Maven), io.fabric8:kubernetes-client (Maven), io.fabric8:kubernetes-client (Maven), io.fabric8:kubernetes-client (Maven). Ecosystems affected: Maven.

How do I fix CVE-2021-20218?

Update io.fabric8:kubernetes-client to 4.7.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-20218 is resolved across your whole dependency graph.

How do I detect CVE-2021-20218 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.fabric8:kubernetes-client, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-20218 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2021-20218 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-20218 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-2021-20218?

CVE-2021-20218 has an EPSS (Exploit Prediction Scoring System) score of 1.3%, placing it in the 71th 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-2021-20218?

CVE-2021-20218 is classified as Path Traversal (CWE-22). 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-2021-20218 published, and has it been updated?

CVE-2021-20218 was published on March 16, 2021 and was last updated on October 24, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

HIGH severity

CVE-2021-20218 — kubernetes-client

HIGH

CVE-2021-20218 is a high-severity (CVSS 7.4) Path Traversal vulnerability in io.fabric8:kubernetes-client. A fix is available for io.fabric8:kubernetes-client — see the affected versions and patch details below.

Improper Limitation of a Pathname to a Restricted Directory in Fabric8 Kubernetes Client

Also known asGHSA-jwh2-ffg4-48xc

Published

Mar 16, 2021

Updated

Oct 24, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs71th percentile — riskier than 71% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

4 pkgs affected

☕io.fabric8:kubernetes-client☕io.fabric8:kubernetes-client☕io.fabric8:kubernetes-client☕io.fabric8:kubernetes-client

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

Description

A flaw was found in the fabric8 kubernetes-client in version 4.2.0 and after. This flaw allows a malicious pod/container to cause applications using the fabric8 kubernetes-client copy command to extract files outside the working path. The highest threat from this vulnerability is to integrity and system availability. This has been fixed in kubernetes-client-4.13.2 kubernetes-client-5.0.2 kubernetes-client-4.11.2 kubernetes-client-4.7.2

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`io.fabric8:kubernetes-client`	≥ 4.2.0&&< 4.7.2	4.7.2`io.fabric8:kubernetes-client:4.7.2`
☕Maven	`io.fabric8:kubernetes-client`	≥ 4.8.0&&< 4.11.2	4.11.2`io.fabric8:kubernetes-client:4.11.2`
☕Maven	`io.fabric8:kubernetes-client`	≥ 4.12.0&&< 4.13.2	4.13.2`io.fabric8:kubernetes-client:4.13.2`
☕Maven	`io.fabric8:kubernetes-client`	≥ 5.0.0&&< 5.0.2	5.0.2`io.fabric8:kubernetes-client:5.0.2`

Affected Products

9 products · 12 configurations

Application

a-mq onlineredhat

all

Application

build of quarkusredhat

all

Application

codeready studioredhat

1 version

12.0

Application

descision managerredhat

1 version

7.0

Application

integration camel kredhat

all

Application

jboss fuseredhat

1 version

7.0.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.fabric8:kubernetes-client, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.fabric8:kubernetes-client to 4.7.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-20218 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

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

In OpenShift Container Platform 4 (OCP) there are no plans to maintain the ose-logging-elasticsearch5 container, therefore it has been marked wontfix at this time and maybe fixed in a future update. Red Hat CodeReady WorkSpaces 2.7.0 does not ship fabric8-kubernetes-client and is therefore not affected by this flaw.

Product	Fixed in	Advisory
Red Hat AMQ Online 1.7.0 GA	`kubernetes-client`	RHSA-2021:0986
Red Hat Fuse 7.10	`kubernetes-client`	RHSA-2021:5134
Red Hat Integration	see advisory	RHSA-2021:3205
Red Hat Integration Camel Quarkus 2	see advisory	RHSA-2021:3207
Red Hat OpenShift Container Platform 4.7	`jenkins-2-plugins-0:4.7.1616671397-1.el8`	RHSA-2021:1006
Red Hat OpenShift Container Platform 4.8	`openshift4/driver-toolkit-rhel8:v4.8.0-202107210116.p0.git.37de0e6.assembly.stream`	RHSA-2021:2438
RHDM 7.12.0	`kubernetes-client`	RHSA-2022:0297
RHPAM 7.12.0	`kubernetes-client`	RHSA-2022:0296

Frequently Asked Questions

A flaw was found in the fabric8 kubernetes-client in version 4.2.0 and after. This flaw allows a malicious pod/container to cause applications using the fabric8 kubernetes-client `copy` command to extract files outside the working path. The highest threat from this vulnerability is to integrity and system availability. This has been fixed in kubernetes-client-4.13.2 kubernetes-client-5.0.2 kubernetes-client-4.11.2 kubernetes-client-4.7.2

O3 Security · Impact-Aware SCA

Is CVE-2021-20218 in your dependencies?

Find it across Maven, including transitive dependencies.

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CVSS Score

7.4/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

High

Raw vector

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

CWE Classification

CWE-22Path Traversal

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

OpenSSF Scorecard

Package health score

kubernetes-client

5.9/10

Maintained10/10

Code-Review7/10

Branch-Protection1/10

Assessed Oct 19, 2026

Timeline

Disclosed

Mar 16, 2021

Last updated

Oct 24, 2026

Identifiers

CVE-2021-20218

GHSA-jwh2-ffg4-48xc

References

Advisorynvd.nist.gov · CVE 2021 20218 Fixgithub.com Reportbugzilla.redhat.com · show bug.cgi

Related vulnerabilities

Also affects kubernetes-client

This CVE is high severity — higher than any of the other 1 CVE affecting kubernetes-client (highest there: moderate).

CVE-2021-4178

Same weakness: CWE-22

This CVE is high severity; 4 of 7 other CVEs with CWE-22 are rated as high or higher (top: high).

CVE-2026-102943CVE-2026-123368CVE-2026-63436CVE-2026-87008CVE-2026-108262CVE-2026-63395CVE-2026-63478Browse all CWE-22

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 24, 2026

CVE-2021-20218 — kubernetes-client

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-2021-20218 in your dependencies?