CVE-2021-25738: Loading specially-crafted yaml with the Kubernetes Java Client library can lead to code execution.

Routine

MEDIUM 6.7WATCHLISTUPGRADE

CVE-2021-25738 is a medium-severity flaw (CVSS 6.7) affecting java. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	6.7 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	0.5% (top 59%)
CISA exploited list	No
Weakness	CWE-20, CWE-502
Published	2021-10-11
Last modified	2026-06-17

Publisher (CNA): Kubernetes · Vendor: kubernetes

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-10-11 19:15 UTCPublished CVE record published
2026-06-17 03:42 UTCUpdated Record last modified

kubernetes java UPGRADE

Affected: <= 9.0.2 · >= 10.0.0 and <= 10.0.1 · >= 11.0.0 and < 11.0.1

Fixed in: 11.0.1

Safe to downgrade to: a release before 10.0.0

1. Check installed version

apt-cache policy java || rpm -q java || java --version

2. UPGRADE to 11.0.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade java

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade java

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 10.0.0 (Debian / Ubuntu)

apt-cache madison java sudo apt install java=<VERSION_BEFORE_10.0.0> sudo apt-mark hold java

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list java sudo dnf downgrade java-<VERSION_BEFORE_10.0.0> sudo dnf versionlock add java

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-25738?

java: upgrade to 11.0.1. Exact commands for each OS are on this page.

Is CVE-2021-25738 being exploited?

CVE-2021-25738 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-25738 affect?

CVE-2021-25738 affects java. Severity is medium (CVSS 6.7). Loading specially-crafted yaml with the Kubernetes Java Client library can lead to code execution.

How urgent is CVE-2021-25738?

Priority 39/100. On your watchlist

Software pages

Java vulnerabilities · Kubernetes vulnerabilities

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References

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