{
  "id": "CVE-2026-45363",
  "url": "https://spydr.io/cve/CVE-2026-45363",
  "published": "2026-07-14T22:16:54.463Z",
  "modified": "2026-09-19T18:16:48.657Z",
  "score": 9.1,
  "severity": "critical",
  "cvss_version": "3.1",
  "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
  "score_source": "github.com",
  "epss": 0.00364,
  "epss_percentile": 0.28,
  "exploited": false,
  "kev": null,
  "ssvc_exploitation": "none",
  "vendors": [
    "jwt"
  ],
  "products": [
    "jwt ruby-jwt"
  ],
  "cwes": [
    "CWE-287",
    "CWE-326",
    "CWE-1391"
  ],
  "description": "ruby-jwt is a Ruby implementation of the RFC 7519 OAuth JSON Web Token standard. Prior to 2.10.3 and 3.2.0, JWT.decode(token, '', true, algorithm: 'HS256') accepts an attacker-forged token because OpenSSL::HMAC.digest('SHA256', '', payload) returns a valid digest under an empty key and no empty-key precondition exists in the HMAC algorithm. The same path is reached when a keyfinder block or key_finder: argument returns an empty string, nil, or an array containing nil for an unknown key, affecting HS256, HS384, and HS512 verification through JWT.decode and JWT::EncodedToken#verify_signature!. This issue is fixed in versions 2.10.3 and 3.2.0.",
  "status": "Deferred",
  "score_type": "Secondary",
  "scores": {
    "cvss_v40": null,
    "cvss_v31": 9.1,
    "cvss_v30": null
  },
  "references": [
    {
      "url": "https://github.com/jwt/ruby-jwt/commit/9820020869ad147b941e49d96ab8beba35532964",
      "tags": []
    },
    {
      "url": "https://github.com/jwt/ruby-jwt/commit/db560b769a07bd9724e77ff505011ac01872106f",
      "tags": []
    },
    {
      "url": "https://github.com/jwt/ruby-jwt/releases/tag/v2.10.3",
      "tags": []
    },
    {
      "url": "https://github.com/jwt/ruby-jwt/releases/tag/v3.2.0",
      "tags": []
    },
    {
      "url": "https://github.com/jwt/ruby-jwt/security/advisories/GHSA-c32j-vqhx-rx3x",
      "tags": []
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2026/09/msg00022.html",
      "tags": []
    }
  ],
  "nvd_url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45363",
  "covered_in": [],
  "attribution": [
    {
      "source": "NVD",
      "url": "https://nvd.nist.gov",
      "notice": "This product uses data from the NVD API but is not endorsed or certified by the NVD."
    },
    {
      "source": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "notice": "Known exploited vulnerabilities from the CISA KEV catalog."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss",
      "notice": "Exploit prediction scores from FIRST EPSS."
    }
  ]
}