CVE-2026-102266

{
  "etk_id": "ETK-2026-22",
  "cve_id": "CVE-2026-102266",
  "display_id": "CVE-2026-102266",
  "ghsa_id": "GHSA-9j54-fg26-wv3r",
  "euvd_id": "EUVD-2026-88484",
  "status": "published",
  "anchor_state": "anchored",
  "title": "Empty HMAC JWK authentication bypass in PyJWT",
  "summary": "PyJWT versions 2.13.0 through 2.13.x can accept forged HS256 tokens when verification uses a PyJWK or PyJWKSet entry containing an empty symmetric key. An attacker can impersonate authenticated users or supply arbitrary claims if the application has such an empty `oct` JWK configured.",
  "mitigation": "Upgrade PyJWT to version 2.14.0 or later. Audit configured JWK sets for empty symmetric keys and reject them; enable minimum HMAC key-length enforcement until the upgrade is complete.",
  "vendor": "pip",
  "product": "pip:PyJWT",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        "2.13.0"
      ],
      "ecosystem": "pip",
      "fixed_versions": [
        "2.14.0"
      ],
      "package_name": "PyJWT",
      "purl": "pkg:pypi/PyJWT"
    }
  ],
  "cwes": [
    347
  ],
  "cvss_score": 7.4,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
  "epss_score": 0.0018,
  "epss_percentile": 0.0736,
  "epss_asof": "2026-10-20",
  "automation": "contextual",
  "check": true,
  "check_confidence_basis": "mechanism_verified",
  "exploit": false,
  "pipeline_minutes": 12.846870283333333,
  "t0_at": "2026-09-28T20:21:26.164000+00:00",
  "signals": {
    "check": {
      "at": "2026-09-29T21:59:57.025947+00:00",
      "days": 1.0684127540162036,
      "is_lower_bound": false,
      "measured_at": "2026-09-28T20:21:26.164000+00:00",
      "url": null
    },
    "public_poc": {
      "at": "2026-09-29T23:43:19+00:00",
      "days": 1.140194861111111,
      "is_lower_bound": false,
      "measured_at": "2026-09-28T20:21:26.164000+00:00",
      "url": "https://github.com/advisories/GHSA-9j54-fg26-wv3r"
    },
    "trigger_signal": {
      "at": "2026-09-28T20:21:26.164000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-09-28T20:21:26.164000+00:00",
      "url": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-9j54-fg26-wv3r"
    }
  }
}