Helm Charts with Specific JSON Schema Values Can Cause Memory Exhaustion in helm.sh/helm (CVE-2025-55199) | HOL Guard CVE

Medium · CVSS 6.5CVE-2025-55199GHSA-9H84-QMV7-982P

Helm Charts with Specific JSON Schema Values Can Cause Memory Exhaustion in helm.sh/helm

Answer in brief

CVE-2025-55199 records a Medium severity (CVSS 6.5) vulnerability in Helm Charts with Specific JSON Schema Values Can Cause Memory Exhaustion in helm.sh/helm. The current sources do not mark it as known exploited. The current feed maps helm.sh/helm (go), 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 Aug 7, 2026Material review Sep 10, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.5
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
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 (go), 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/helmgo	>=0	Not reported
helm.sh/helm/v3go	>=0 <3.18.5	3.18.5

Recommended response

Check inventory. Check lockfiles and deployed manifests for helm.sh/helm, 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
Aug 7, 2026

Sources and claim methodology

Upstream source description

A Helm contributor discovered that it was possible to craft a JSON Schema file in a manner which could cause Helm to use all available memory and have an out of memory (OOM) termination. ### Impact A malicious chart can point `$ref` in _values.schema.json_ to a device (e.g. `/dev/*`) or other problem file which could cause Helm to use all available memory and have an out of memory (OOM) termination. ### Patches This issue has been resolved in Helm v3.18.5. ### Workarounds Make sure that all Helm charts that are being loaded into Helm doesn't have any reference of `$ref` pointing to `/dev/zero`. ### 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.