CVE-2026-35204: Helm path traversal in plugin metadata version field

CVE-2026-35204 · Severity: high · CVSS 8.6 · Published 2026-04-09

Helm is a popular package manager used to manage applications on Kubernetes. A security flaw allows a malicious plugin to write files to any location on a user's computer when the plugin is installed or updated. This could allow an attacker to overwrite critical system files or steal sensitive data, potentially leading to a full system compromise.

Technologies: helm.sh/helm/v4 (Go), Helm. Vendors: Go, Helm.

Quick answers

Is CVE-2026-35204 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-35204 being exploited in the wild.
How severe is CVE-2026-35204?
High severity, with a CVSS score of 8.6, published 9 April 2026.
Which products and versions are affected?
helm.sh/helm/v4 (Go) >= 4.0.0, <= 4.1.3, SEMVER:introduced=4.0.0,fixed=4.1.4; Helm >= 4.0.0, < 4.1.4.
Is there a fix for CVE-2026-35204?
Yes. helm.sh/helm/v4 (Go): upgrade to 4.1.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-35204 attacked?
It is attacked with local access, in a software library.
Am I affected by CVE-2026-35204?
Check whether you run helm.sh/helm/v4 (Go) or Helm at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • helm.sh/helm/v4 (Go): upgrade to 4.1.4 or later
    go get helm.sh/helm/v4@v4.1.4

Technical details

A path traversal vulnerability (CWE-22) exists in Helm's plugin loading mechanism. The root cause is a failure to validate the 'version' field within a plugin's 'plugin.yaml' file, which can be manipulated to include POSIX dot-dot ('../') path separators. When a user installs or updates a specially crafted plugin, Helm uses this version string to construct a filesystem path, allowing the plugin's contents to be written outside the intended directory. This can lead to arbitrary file overwrite and potential code execution if system binaries or configuration files are replaced. The issue is fixed in version 4.1.4 by enforcing strict semantic versioning (SemVer) validation on the version field.

Affected products

  • Helm Helm >= 4.0.0, < 4.1.4

Identifiers

  • CVE-2026-35204
  • GHSA-vmx8-mqv2-9gmg
  • GO-2026-5666

Timeline

  • 2026-04-09: advisory: Vendor advisory and GHSA published.
  • 2026-04-09: patched: Fixed in Helm version 4.1.4.

References

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