CVE-2026-48524

{
  "id": "CVE-2026-48524",
  "sourceIdentifier": "[email protected]",
  "published": "2026-05-28T16:16:29.403",
  "lastModified": "2026-10-26T13:10:00.140",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, PyJWKClient.get_signing_key() forces a fresh HTTP request to the JWKS endpoint for every JWT with an unknown kid value, with no rate limiting. Since kid comes from the unverified token header, an attacker can trigger unlimited outbound requests. The vulnerability surfaces only when a JWKS fetch fails; an attacker can attempt to provoke that with sustained unknown-kid traffic, but the outcome depends on upstream JWKS-endpoint behavior (rate limiting, transient errors) which is beyond the attacker's control. This vulnerability is fixed in 2.13.0."
    },
    {
      "lang": "es",
      "value": "PyJWT es una implementación de JSON Web Token en Python. Antes de la versión 2.13.0, PyJWKClient.get_signing_key() fuerza una nueva solicitud HTTP al endpoint JWKS para cada JWT con un valor kid desconocido, sin limitación de tasa. Dado que kid proviene del encabezado del token no verificado, un atacante puede desencadenar solicitudes salientes ilimitadas. La vulnerabilidad solo se manifiesta cuando una obtención de JWKS falla; un atacante puede intentar provocar eso con tráfico sostenido de kid desconocido, pero el resultado depende del comportamiento del endpoint JWKS ascendente (limitación de tasa, errores transitorios) lo cual está fuera del control del atacante. Esta vulnerabilidad está corregida en la versión 2.13.0."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "jpadilla",
          "product": "pyjwt",
          "versions": [
            {
              "version": "< 2.13.0",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "baseScore": 3.7,
          "baseSeverity": "LOW",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 1.4
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-05-28T19:16:33.339327Z",
          "id": "CVE-2026-48524",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-460"
        },
        {
          "lang": "en",
          "value": "CWE-755"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:pyjwt_project:pyjwt:*:*:*:*:*:*:*:*",
              "versionEndExcluding": "2.13.0",
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  "references": [
    {
      "url": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-fhv5-28vv-h8m8",
      "source": "[email protected]",
      "tags": [
        "Mitigation",
        "Vendor Advisory"
      ]
    }
  ]
}