Helm May Panic Due To Incorrect YAML Content

Answer in brief

CVE-2025-55198 records a Medium severity (CVSS 6.5) vulnerability in Helm May Panic Due To Incorrect YAML Content. The current sources do not mark it as known exploited. The current feed maps helm.sh/helm/v3 (go). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 14, 2025Updated Sep 10, 2026Source checked Sep 10, 2026First seen by HOL Sep 10, 2026Material review Sep 10, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.5
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 6.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps helm.sh/helm/v3 (go). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
helm.sh/helm/v3go	>=0 <3.18.5	3.18.5

Recommended response

Check inventory. Check lockfiles and deployed manifests for helm.sh/helm/v3.
Review the reported fix. Update helm.sh/helm/v3 to 3.18.5 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 14, 2025
Evidence: source:osv:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:record
First seen by HOL
Sep 10, 2026

Sources and claim methodology

Upstream source 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](https://github.com/helm/community/blob/master/SECURITY.md) document. ### Credits Disclosed by Jakub Ciolek at AlphaSense.

Quoted source text, attributed separately from HOL analysis.