How severe is CVE-2021-25738?

CVE-2021-25738 has a CVSS score of 6.7/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-25738?

CVE-2021-25738 affects the following packages: io.kubernetes:client-java (Maven). Ecosystems affected: Maven.

How do I fix CVE-2021-25738?

Update io.kubernetes:client-java to 11.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-25738 is resolved across your whole dependency graph.

How do I detect CVE-2021-25738 in my Maven dependencies?

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

How do I mitigate CVE-2021-25738 if there is no patch (or I can't update yet)?

Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Is CVE-2021-25738 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-25738 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-2021-25738?

CVE-2021-25738 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 39th 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-2021-25738?

CVE-2021-25738 is classified as Improper Input Validation (CWE-20), Deserialization of Untrusted Data (CWE-502). These weakness types 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-2021-25738 published, and has it been updated?

CVE-2021-25738 was published on October 11, 2021 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.

☕

☕ Maven

Not in CISA KEV

MEDIUM severity

CVE-2021-25738 — client-java

MEDIUM

CVE-2021-25738 is a medium-severity (CVSS 6.7) Improper Input Validation vulnerability in io.kubernetes:client-java. A fix is available for io.kubernetes:client-java — see the affected versions and patch details below.

Code injection in Kubernetes Java Client

Also known asGHSA-m8wh-mqgf-rr8g

Published

Oct 11, 2021

Updated

Aug 7, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

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

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs39th percentile — riskier than 39% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2021-25738 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

☕io.kubernetes:client-java

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

Loading specially-crafted yaml with the Kubernetes Java Client library can lead to code execution.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`io.kubernetes:client-java`	all versions	11.0.1`io.kubernetes:client-java:11.0.1`

Affected Products

1 product · 3 configurations

Application

javakubernetes

≥ 11.0.0 && ≤ 10.0.1

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.kubernetes:client-java, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.kubernetes:client-java to 11.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-25738 is resolved across your whole dependency graph.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Frequently Asked Questions

Loading specially-crafted yaml with the Kubernetes Java Client library can lead to code execution.

O3 Security · Impact-Aware SCA

Is CVE-2021-25738 in your dependencies?

Find it across Maven, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

6.7/10CVSS v3 base

Vector breakdown

Attack Vector

Local

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Raw vector

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

CWE Classification

CWE-20Improper Input Validation CWE-502Deserialization of Untrusted Data

Weaponization

No known public exploit tooling found.

OpenSSF Scorecard

Package health score

java

6.1/10

Maintained10/10

Code-Review10/10

Branch-ProtectionN/A

Assessed Oct 5, 2026

Timeline

Disclosed

Oct 11, 2021

Last updated

Aug 7, 2026

Identifiers

CVE-2021-25738

GHSA-m8wh-mqgf-rr8g

References

Advisoryopenwall.com Advisorygroups.google.com Advisorynvd.nist.gov Reportgithub.com Packagegithub.com

Related vulnerabilities

Also affects client-java

This CVE is medium severity; 1 of 1 other CVE affecting client-java is rated as high or higher (top: high).

CVE-2020-8570

Same weakness: CWE-20

This CVE is medium severity; 6 of 7 other CVEs with CWE-20 are rated as high or higher (top: high).

CVE-2026-61794CVE-2026-81875CVE-2026-81876CVE-2026-61793GHSA-2xmm-m4wv-3fjhCVE-2026-56831CVE-2026-54529Browse all CWE-20

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedAug 7, 2026

CVE-2021-25738 — client-java

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

Frequently Asked Questions

Is CVE-2021-25738 in your dependencies?