CVE-2026-35205: Helm's plugin verification fails open when .prov is missing, allowing unsigned plugin install

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-09 · updated 2026-07-15
Weakness: CWE-636

Description

Helm is a package manager for Charts for Kubernetes. From 4.0.0 to 4.1.3, Helm will install plugins missing provenance (.prov file) when signature verification is required. This vulnerability is fixed in 4.1.4.

Affected products

helm: from 4.0.0 before 4.1.4 — fixed in 4.1.4

How to fix

Upgrade to a fixed version: helm 4.1.4. Check the vendor advisory for mitigations.

References

https://github.com/helm/helm/commit/05fa37973dc9e42b76e1d2883494c87174b6074f
https://github.com/helm/helm/releases/tag/v4.1.4
https://github.com/helm/helm/security/advisories/GHSA-q5jf-9vfq-h4h7
https://helm.sh/docs/topics/provenance/#the-provenance-file
https://access.redhat.com/errata/RHSA-2026:26441
https://access.redhat.com/security/cve/CVE-2026-35205
https://bugzilla.redhat.com/show_bug.cgi?id=2456927
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-35205.json

Get alerted when CVE-2026-35205 or the next vulnerability affects your stack