CVE-2025-32387: Helm.sh/helm/v3 Helm Allows A Specially Crafted Vulnerability

MODERATE
Advisory Identifier: GHSA-5xqw-8hwv-wg92
CVSS 6.5
CWE-121 CWE-674
Published
Advisory Summary

CVE-2025-32387 is a MODERATE (CVSS 6.5) helm allows a specially crafted vulnerability (CWE-121: Stack-based Buffer Overflow) affecting Helm.sh/helm/v3 libraries in the Go ecosystem. The issue involves helm allows a specially crafted json schema to cause a stack overflow. Remediation is available by upgrading affected packages to version 3.17.3.

CVE-2025-32387 at a Glance

CVE Identifier CVE-2025-32387
GHSA Identifier GHSA-5xqw-8hwv-wg92
Severity MODERATE
CVSS v3.1 Base Score 6.5
CWE Classification CWE-121: Stack-based Buffer Overflow
Affected Product Helm.sh/helm/v3
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 6.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2025-32387

To remediate this vulnerability, upgrade all affected Helm.sh/helm/v3 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

helm.sh/helm/v3 fixed: 3.17.3
Upgrade helm.sh/helm/v3 to 3.17.3
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for helm.sh/helm/v3

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-32387, inspect your project dependencies for Helm.sh/helm/v3:

inspect dependencies for helm.sh/helm/v3

Analyze the terminal output to locate any version of Helm.sh/helm/v3 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.17.3), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-121: Stack-based Buffer Overflow, where a stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). In Helm.sh/helm/v3, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A Helm contributor discovered that a specially crafted JSON Schema within a chart can lead to a stack overflow. ### Impact 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. ### Patches This issue has been resolved in Helm v3.17.3. ### Workarounds Ensure that the JSON Schema within any charts loaded by Helm does not have a large number of nested references. These JSON Schema files are larger than 10 MiB. ### For more information 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.

CVE-2025-32387 Affected Helm.sh/helm/v3 Versions

1 component(s)
Fixed Versions:
3.17.3
Product / Package Ecosystem Affected Versions Fixed Version
helm.sh/helm/v3
Go
< 3.17.3
3.17.3

References

Frequently Asked Questions

What is CVE-2025-32387?
CVE-2025-32387 is a security vulnerability in Helm.sh/helm/v3 involving Helm Allows A Specially Crafted JSON Schema To Cause A Stack Overflow under CWE-121: Stack-based Buffer Overflow.
Which Helm.sh/helm/v3 versions are affected?
Affected versions include releases prior to 3.17.3 across affected packages: helm.sh/helm/v3.
What version fixes CVE-2025-32387?
Upgrading to 3.17.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is helm.sh/helm/v3 affected?
Yes, helm.sh/helm/v3 is affected in releases prior to 3.17.3. Upgrade your dependency to 3.17.3 or later.
What is the CVSS score of CVE-2025-32387?
CVE-2025-32387 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2025-32387?
CVE-2025-32387 is classified under CWE-121: Stack-based Buffer Overflow (A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).).
How can I check Go dependencies for CVE-2025-32387?
Run the dependency tree command: 'inspect dependencies for helm.sh/helm/v3'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-5xqw-8hwv-wg92",
  "modified" : "2025-04-10T13:48:31Z",
  "published" : "2025-04-10T13:48:31Z",
  "aliases" : [ "CVE-2025-32387" ],
  "summary" : "Helm Allows A Specially Crafted JSON Schema To Cause A Stack Overflow",
  "details" : "A Helm contributor discovered that a specially crafted JSON Schema within a chart can lead to a stack overflow.\n\n### Impact\nA 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. \n\n### Patches\nThis issue has been resolved in Helm v3.17.3.\n\n### Workarounds\nEnsure that the JSON Schema within any charts loaded by Helm does not have a large number of nested references. These JSON Schema files are larger than 10 MiB.\n\n### For more information\nHelm's security policy is spelled out in detail in our [SECURITY](https://github.com/helm/community/blob/master/SECURITY.md) document.\n\n### Credits\nDisclosed by Jakub Ciolek at AlphaSense.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "helm.sh/helm/v3"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.17.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/helm/helm/security/advisories/GHSA-5xqw-8hwv-wg92"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-32387"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/helm/helm/commit/d8ca55fc669645c10c0681d49723f4bb8c0b1ce7"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/helm/helm"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-121", "CWE-674" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-04-10T13:48:31Z",
    "nvd_published_at" : "2025-04-09T23:15:37Z"
  }
}