CVE-2026-35204: Helm has a path traversal in plugin metadata version enables arbitrary file write outside Helm plugin directory
Helm is a package manager for Charts for Kubernetes. From 4.0.0 to 4.1.3, a specially crafted Helm plugin, when installed or updated, will cause Helm to write the contents of the plugin to an arbitrary filesystem location. To prevent this, validate that the plugin.yaml of the Helm plugin does not include a version: field containing POSIX dot-dot path separators ie. "/../". This vulnerability is fixed in 4.1.4.
Other sources
Helm is a package manager for Charts for Kubernetes. In Helm versions >=4.0.0 and <=4.1.3, a specially crafted Helm plugin, when installed or updated, will cause Helm to write the contents of the plugin to an arbitrary filesystem location.
Impact
A Helm user who installs or updates a plugin that is specially crafted can cause Helm to attempt to write the content of the affected plugin to an arbitrary location on the user's filesystem. Impacted users risk potentially overwriting user and system files which may further compromise the integrity of a system.
Patches
This issue has been patched in Helm v4.1.4
Installing/updating a plugin with a non-SemVer version (which excludes path traversal patterns) will result in an error.
Workarounds
Validate that the plugin.yaml of the Helm plugin does not include a version: field containing POSIX dot-dot path separators ie. "/../".
— GitHub
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
go/helm.sh/helm/v4to a version that resolves this vulnerability.Fixed in 4.1.4 - Upgrade
Upgrade
Helmto a version that resolves this vulnerability.Fixed in 4.1.4 - Configuration
When installing/updating a Helm plugin, validate that the plugin's `plugin.yaml` does not include a `version:` field containing POSIX dot-dot path separators (e.g., sequences like `../`), to prevent arbitrary file write. Note: Installing/updating with a non-SemVer version is expected to result in an error.
Helm plugin deployment plugin.yaml version field validation = Disallow POSIX dot-dot path separators in the plugin.yaml `version:` field
Event History
Frequently Asked Questions
What is the severity of CVE-2026-35204?
CVE-2026-35204 is considered a high severity vulnerability due to its potential for arbitrary file writes leading to system compromise.
How do I fix CVE-2026-35204?
To fix CVE-2026-35204, upgrade Helm to version 4.1.4 or later.
What versions of Helm are affected by CVE-2026-35204?
Helm versions 4.0.0 to 4.1.3 are affected by CVE-2026-35204.
What is the nature of the vulnerability in CVE-2026-35204?
CVE-2026-35204 involves a path traversal in plugin metadata allowing for arbitrary file writes outside the Helm plugin directory.
Can CVE-2026-35204 be exploited remotely?
Yes, CVE-2026-35204 can potentially be exploited remotely if a user installs or updates a specially crafted Helm plugin.