{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "2.0.0a1"
              },
              {
                "fixed": "2.15.0"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "8041cb607a733a9b5fffe1e9136d55a40bcea25b"
            },
            {
              "fixed": "5fde08a6cf906aa7698de2d6391d88b73006b17b"
            },
            {
              "fixed": "1d41a6478e1562e68ff667fcd703356acf085f68"
            }
          ],
          "repo": "https://github.com/jpadilla/pyjwt",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-42vr-xj54-vc7v"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-248"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101918.json"
  },
  "details": "PyJWT is a Python implementation of JSON Web Token standards. From 2.0.0a1 until 2.15.0, PyJWT PyJWKClient.get_signing_key_from_jwt is affected because payload parser catches ValueError but not RecursionError. This occurs when an attacker-controlled recursively nested payload reaches json.loads. As a result, documented PyJWT exception handling does not contain the failure. Consequently, an unauthenticated request can raise an exception that may produce an HTTP 500 response. The advisory-defined affected implementation also includes jwt/api_jwt.py, verify_signature=False. This issue is fixed in version 2.15.0.",
  "id": "CVE-2026-101918",
  "modified": "2026-09-30T03:31:04.739695174Z",
  "published": "2026-09-28T20:11:55.278Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/jpadilla/pyjwt/releases/tag/2.15.0"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101918.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-42vr-xj54-vc7v"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-101918"
    },
    {
      "type": "FIX",
      "url": "https://github.com/jpadilla/pyjwt/commit/5fde08a6cf906aa7698de2d6391d88b73006b17b"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "PyJWT: Unauthenticated RecursionError DoS in pre-verification payload parse (PyJWKClient.get_signing_key_from_jwt / verify_signature=False)"
}