{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:pyjwt_project:pyjwt:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "2.8.0"
              },
              {
                "fixed": "2.13.0"
              },
              {
                "last_affected": "2.12.1"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "CPE_RANGE"
            ]
          },
          "events": [
            {
              "introduced": "72ad55f6d7041ae698dc0790a690804118be50fc"
            },
            {
              "fixed": "7144e4534c34810f4525dc4578a32addd8212cff"
            }
          ],
          "repo": "https://github.com/jpadilla/pyjwt",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-w7vc-732c-9m39"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-400"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48525.json"
  },
  "details": "PyJWT is a JSON Web Token implementation in Python. From 2.8.0 to 2.12.1, when verifying detached JWS tokens using the unencoded-payload option (\"b64\": false, RFC 7797), PyJWT performs Base64URL decoding of the compact-serialization payload segment before enforcing the detached-payload rules. For b64=false, PyJWT later discards that decoded payload and replaces it with the caller-provided detached_payload. In practice, this turns the middle segment into an attacker-controlled “work amplifier”: a remote client can supply an arbitrarily large Base64URL payload segment that forces CPU work + memory allocations even if the signature is invalid. This creates an unauthenticated DoS vector against any endpoint that verifies detached JWS using PyJWT. This vulnerability is fixed in 2.13.0.",
  "id": "CVE-2026-48525",
  "modified": "2026-07-15T01:48:56.653717330Z",
  "published": "2026-05-28T15:11:12.483Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48525.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-w7vc-732c-9m39"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48525"
    }
  ],
  "schema_version": "1.8.0",
  "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 DoS via unbounded Base64URL decoding of unused payload segment in b64=false detached JWS"
}