Helm's plugin verification fails open when .prov is missing, allowing unsigned plugin install

{
  "id": "930b919f6c4f176a08398d484015537f3b83368b61aa7805dc553166d8127e98",
  "url": "https://osv.dev/vulnerability/CVE-2026-35205",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Helm's plugin verification fails open when .prov is missing, allowing unsigned plugin install",
    "summary": "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.",
    "evidence": "osv:CVE-2026-35205",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-35205",
      "aliases": [
        "BIT-helm-2026-35205",
        "CVE-2026-35205",
        "GHSA-q5jf-9vfq-h4h7",
        "GO-2026-5566"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/helm/helm",
              "type": "GIT",
              "events": [
                {
                  "introduced": "99cd1964357c793351be481d55abbe21c6b2f4ec"
                },
                {
                  "fixed": "05fa37973dc9e42b76e1d2883494c87174b6074f"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "4.0.0"
                      },
                      {
                        "fixed": "4.1.4"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "05fa37973dc9e42b76e1d2883494c87174b6074f"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "05fa37973dc9e42b76e1d2883494c87174b6074f"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v4.1.4"
                  },
                  {
                    "cpe": "cpe:2.3:a:helm:helm:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "4.0.0"
                      },
                      {
                        "fixed": "4.1.4"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v4.1.3",
            "v4.1.2",
            "v4.1.1",
            "v4.1.0-rc.1",
            "v4.1.0",
            "v4.0.0-rc.1",
            "v4.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-35205.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:21.052181057Z",
      "provider": "osv",
      "references": [
        "https://github.com/helm/helm/releases/tag/v4.1.4",
        "https://helm.sh/docs/topics/provenance/#the-provenance-file",
        "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-35205.json",
        "https://access.redhat.com/errata/RHSA-2026:26441",
        "https://access.redhat.com/security/cve/CVE-2026-35205",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35205.json",
        "https://github.com/helm/helm/security/advisories/GHSA-q5jf-9vfq-h4h7",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-35205",
        "https://bugzilla.redhat.com/show_bug.cgi?id=2456927",
        "https://github.com/helm/helm/commit/05fa37973dc9e42b76e1d2883494c87174b6074f"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-636"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35205.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-35205",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 487207,
  "published_at": "2026-04-09T15:06:41.052+00:00"
}