ubuntu-cve-2026-45363
Vulnerability from osv_ubuntu
Published
2026-07-14 22:16
Modified
2026-07-14 22:16
Summary
Details

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.

Severity
9.1 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-jwt",
            "binary_version": "1.0.0-3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "ruby-jwt",
        "purl": "pkg:deb/ubuntu/ruby-jwt@1.0.0-3?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0.0-3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-jwt",
            "binary_version": "1.5.6-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "ruby-jwt",
        "purl": "pkg:deb/ubuntu/ruby-jwt@1.5.6-1?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.5.6-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-jwt",
            "binary_version": "2.1.0-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "ruby-jwt",
        "purl": "pkg:deb/ubuntu/ruby-jwt@2.1.0-2?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.5.6-1",
        "2.1.0-2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-jwt",
            "binary_version": "2.2.2-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "ruby-jwt",
        "purl": "pkg:deb/ubuntu/ruby-jwt@2.2.2-1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.2.2-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-jwt",
            "binary_version": "2.7.1-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "ruby-jwt",
        "purl": "pkg:deb/ubuntu/ruby-jwt@2.7.1-1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.7.0-2",
        "2.7.1-1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "ruby-jwt",
            "binary_version": "2.7.1-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "ruby-jwt",
        "purl": "pkg:deb/ubuntu/ruby-jwt@2.7.1-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.7.1-1"
      ]
    }
  ],
  "aliases": [],
  "details": "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, \u0027\u0027, true, algorithm: \u0027HS256\u0027) accepts an attacker-forged token because OpenSSL::HMAC.digest(\u0027SHA256\u0027, \u0027\u0027, 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.",
  "id": "UBUNTU-CVE-2026-45363",
  "modified": "2026-07-14T22:16:00Z",
  "published": "2026-07-14T22:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-45363"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-45363"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jwt/ruby-jwt/commit/9820020869ad147b941e49d96ab8beba35532964"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jwt/ruby-jwt/commit/db560b769a07bd9724e77ff505011ac01872106f"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jwt/ruby-jwt/releases/tag/v2.10.3"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jwt/ruby-jwt/releases/tag/v3.2.0"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/jwt/ruby-jwt/security/advisories/GHSA-c32j-vqhx-rx3x"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-45363"
  ]
}



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