CVE-2025-55199: Helm Charts with Specific JSON Schema Values Can Cause Memory Exhaustion

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-08-14 · updated 2026-06-17
Weakness: CWE-770

Description

Helm is a package manager for Charts for Kubernetes. Prior to version 3.18.5, it is 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. This issue has been resolved in Helm 3.18.5. A workaround involves ensuring all Helm charts that are being loaded into Helm do not have any reference of $ref pointing to /dev/zero.

Affected products

helm: before 3.18.5 — fixed in 3.18.5

How to fix

Upgrade to a fixed version: helm 3.18.5. Check the vendor advisory for mitigations.

References

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