How severe is CVE-2025-55198?

CVE-2025-55198 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2025-55198?

CVE-2025-55198 affects the following packages: helm.sh/helm/v3 (Go). Ecosystems affected: Go.

How do I fix CVE-2025-55198?

Update helm.sh/helm/v3 to 3.18.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-55198 is resolved across your whole dependency graph.

How do I detect CVE-2025-55198 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for helm.sh/helm/v3, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2025-55198 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2025-55198 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-55198 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-2025-55198?

CVE-2025-55198 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 29th 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-2025-55198?

CVE-2025-55198 is classified as CWE-908 (CWE-908). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2025-55198 published, and has it been updated?

CVE-2025-55198 was published on August 13, 2025 and was last updated on October 28, 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-2025-55198 — helm

MEDIUMFix: helm/helm@ec5f59e

CVE-2025-55198 is a medium-severity (CVSS 6.5) CWE-908 vulnerability in helm.sh/helm/v3. A fix is available for helm.sh/helm/v3 — see the affected versions and patch details below.

Helm May Panic Due To Incorrect YAML Content

Also known asBIT-helm-2025-55198GHSA-f9f8-9pmf-xv68GO-2025-3888

Published

Aug 13, 2025

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

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

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-55198.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk+0.02%

Lower risk than most CVEs29th percentile — riskier than 29% 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

1 pkg affected

🐹helm.sh/helm/v3

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

A Helm contributor discovered an improper validation of type error when parsing Chart.yaml and index.yaml files that can lead to a panic.

Impact

There are two areas of YAML validation that were impacted. First, when a Chart.yaml file had a null maintainer or the child or parent of a dependencies import-values could be parsed as something other than a string, helm lint would panic. Second, when an index.yaml had an empty entry in the list of chart versions Helm would panic on interactions with that repository.

Patches

This issue has been resolved in Helm v3.18.5.

Workarounds

Ensure YAML files are formatted as Helm expects prior to processing them with Helm.

References

Helm's security policy is spelled out in detail in our SECURITY document.

Credits

Disclosed by Jakub Ciolek at AlphaSense.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`helm.sh/helm/v3`	all versions	3.18.5`go get helm.sh/helm/v3@v3.18.5`

Affected Products

1 product · 1 configurations

Application

helmhelm

< 3.18.5

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for helm.sh/helm/v3, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update helm.sh/helm/v3 to 3.18.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-55198 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

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

Workaround published by Red Hat

To mitigate this flaw, ensure YAML files are formatted as Helm expects prior to processing them with Helm.

Source: Red Hat security advisory for CVE-2025-55198 (CC BY 4.0)

Product	Fixed in	Advisory
Red Hat OpenShift Container Platform 4.20	`openshift4/ose-console-rhel9:openshift-enterprise-console-container-v4.20.0-202511250912.p2.ga7d3608.assembly.stream.el9`	RHSA-2025:22257
Red Hat OpenShift Container Platform 4.21	`openshift4/ose-console-rhel9:1770188884`	RHSA-2026:2129

Frequently Asked Questions

A Helm contributor discovered an improper validation of type error when parsing Chart.yaml and index.yaml files that can lead to a panic. ### Impact There are two areas of YAML validation that were impacted. First, when a `Chart.yaml` file had a `null` maintainer or the `child` or `parent` of a dependencies `import-values` could be parsed as something other than a string, `helm lint` would panic. Second, when an `index.yaml` had an empty entry in the list of chart versions Helm would panic on interactions with that repository. ### Patches This issue has been resolved in Helm v3.18.5. ###