CVE-2025-32387: Helm Allows A Specially Crafted JSON Schema To Cause A Stack Overflow

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-04-09 · updated 2026-06-17
Weakness: CWE-121

Description

Helm is a package manager for Charts for Kubernetes. A JSON Schema file within a chart can be crafted with a deeply nested chain of references, leading to parser recursion that can exceed the stack size limit and trigger a stack overflow. This issue has been resolved in Helm v3.17.3.

Affected products

helm: before 3.17.3 — fixed in 3.17.3

How to fix

Upgrade to a fixed version: helm 3.17.3. Check the vendor advisory for mitigations.

References

https://github.com/helm/helm/commit/d8ca55fc669645c10c0681d49723f4bb8c0b1ce7
https://github.com/helm/helm/security/advisories/GHSA-5xqw-8hwv-wg92

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