No exploitation reportedFix available

CVE-2021-20218

Q: Is CVE-2021-20218 actively exploited?

Active exploitation of CVE-2021-20218 has not been confirmed. Its EPSS score was 1.3% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-20218?

CVE-2021-20218 has a CVSS v3 base score of 7.4 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H.

No exploitation reported by the sources we read.

Published2021-03-16
Fixed in5.0.2 · 4.13.2 · 4.11.2 · 4.7.2
WeaknessCWE-22

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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

Timeline

dates in UTC

2021-03-1621:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-20218?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-20218?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV

Redhat kubernetes-client

Branch	Affected	Fixed in	Source
5.0	≥ 5.0.0, < 5.0.2	5.0.2	NVD · OSV
4.x	≥ 4.12.0, < 4.13.2	4.13.2	NVD · OSV
4.x	≥ 4.8.0, < 4.11.2	4.11.2	NVD · OSV
4.x	≥ 4.2.0, < 4.7.2	4.7.2	NVD · OSV

Redhat a-mq online

Branch	Affected	Fixed in	Source
—	all versions	no fix published	NVD

Redhat build of quarkus

Branch	Affected	Fixed in	Source
—	all versions	no fix published	NVD

6 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

RHSA-2021:2438 Red Hat Product Security386 products fixed
Red Hat Security Advisory: OpenShift Container Platform 4.8.2 bug fix and security update

Full record on NVD

Fix

Update Redhat kubernetes-client to 5.0.2 · 4.13.2 · 4.11.2 · 4.7.2
Vendor fix Red Hat Product Security RHSA-2021:2438 · 386 productsFor OpenShift Container Platform 4.8 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this asynchronous errata update: https://docs.openshift.com/container-platform/4.8/release_notes/ocp-4-8-r…

Advisories and patches

bugzilla.redhat.comVendor Advisory
github.comPatch

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.17.4read 2026-10-23
NVDCVSS 2.05.8read 2026-10-23
CNAweakness (CWE)CWE-22read 2026-10-23
FIRST EPSSEPSS score1.3 %2026-10-23
OSVaffected packages—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H
Published: 2021-03-16
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-20218?

Is CVE-2021-20218 actively exploited?

Active exploitation of CVE-2021-20218 has not been confirmed. Its EPSS score was 1.3% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-20218?

CVE-2021-20218 has a CVSS v3 base score of 7.4 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H.

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