Security advisory

{
  "id": "e8dd91c3d66f84e06d503dc904fe2551d8179acc8d5c49866da4f8beb85ae14a",
  "url": "https://osv.dev/vulnerability/CVE-2023-51774",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2023-51774",
    "summary": "The json-jwt (aka JSON::JWT) gem 1.16.3 for Ruby sometimes allows bypass of identity checks via a sign/encryption confusion attack. For example, JWE can sometimes be used to bypass JSON::JWT.decode.",
    "evidence": "osv:CVE-2023-51774",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2023-51774",
      "aliases": [
        "CVE-2023-51774",
        "GHSA-c8v6-786g-vjx6"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/nov/json-jwt",
              "type": "GIT",
              "events": [
                {
                  "introduced": "413848c8c93a99093cbb68f198004848f62ecdbd"
                },
                {
                  "last_affected": "413848c8c93a99093cbb68f198004848f62ecdbd"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:json-jwt_project:json-jwt:1.16.3:*:*:*:*:ruby:*:*",
                    "range": [
                      {
                        "introduced": "1.16.3"
                      },
                      {
                        "last_affected": "1.16.3"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "1.16.3",
            "v1.16.3"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-51774.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:24.950623535Z",
      "provider": "osv",
      "references": [
        "https://github.com/P3ngu1nW/CVE_Request/blob/main/novjson-jwt.md",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/51xxx/CVE-2023-51774.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2023-51774"
      ],
      "provider_metadata": {
        "cna_assigner": "mitre",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/51xxx/CVE-2023-51774.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2023-51774",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 491631,
  "published_at": "2023-12-25T00:00:00+00:00"
}