CVE-2026-104851

{
  "etk_id": "ETK-2026-358",
  "cve_id": "CVE-2026-104851",
  "display_id": "CVE-2026-104851",
  "ghsa_id": "GHSA-27vj-qcqg-25rc",
  "euvd_id": "EUVD-2026-91720",
  "status": "published",
  "anchor_state": "anchored",
  "title": "Server-side template injection in fsspec filesystem_spec",
  "summary": "fsspec filesystem_spec versions 0.9.0 through versions before 2026.6.0 process reference JSON using unsafe template evaluation. An attacker who can supply a reference document or control its source URL may execute Python code when a ReferenceFileSystem is opened, including through applications that use it.",
  "mitigation": "Upgrade filesystem_spec to version 2026.6.0. Until upgraded, do not open untrusted reference JSON documents and restrict reference-document URLs to trusted sources.",
  "vendor": "fsspec",
  "product": "filesystem_spec",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 0.9.0"
      ],
      "ecosystem": "pip",
      "fixed_versions": [
        ">= 2026.6.0"
      ],
      "package_name": "fsspec",
      "purl": "pkg:pypi/fsspec"
    }
  ],
  "cwes": [
    94
  ],
  "cvss_score": 8.8,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
  "epss_score": 0.0032,
  "epss_percentile": 0.2323,
  "epss_asof": "2026-10-20",
  "automation": "contextual",
  "check": true,
  "check_confidence_basis": "mechanism_verified",
  "exploit": false,
  "pipeline_minutes": 15.717199966666668,
  "t0_at": "2026-10-02T16:36:48.513000+00:00",
  "signals": {
    "check": {
      "at": "2026-10-02T17:25:05.732275+00:00",
      "days": 0.033532630497685185,
      "is_lower_bound": false,
      "measured_at": "2026-10-02T16:36:48.513000+00:00",
      "url": null
    },
    "public_poc": {
      "at": "2026-10-05T22:53:22+00:00",
      "days": 3.2614986921296296,
      "is_lower_bound": false,
      "measured_at": "2026-10-02T16:36:48.513000+00:00",
      "url": "https://github.com/advisories/GHSA-27vj-qcqg-25rc"
    },
    "trigger_signal": {
      "at": "2026-10-02T16:36:48.513000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-10-02T16:36:48.513000+00:00",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-104851"
    }
  }
}