« Volver al listado

CVE-2026-35042

Estado: AnalizadaAlta (7.5)—

fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, fast-jwt does not validate the crit (Critical) Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that fast-jwt does not understand, the library accepts the token instead of rejecting it. This violates the MUST requirement in the RFC.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

JWT de red sin autenticación (AV:N/PR:N). Falta validación de crit permite aceptar tokens malformados: escalamiento de sesión/autenticación (T1556, T1078.004). CWE-345 (validación insuficiente) refuerza impacto en autenticación.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Privileged Account ManagementUser Account ManagementPassword PoliciesMulti-factor AuthenticationActive Directory ConfigurationVulnerability Scanning

Tecnologías afectadas (1)

Nearform — Fast-jwt

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-35042",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-35042",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-04-07T15:19:36.239438Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "nearform",
          "product": "fast-jwt",
          "versions": [
            {
              "status": "affected",
              "version": "<= 6.1.0"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-04-06T17:17:13.410",
  "references": [
    {
      "url": "https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6",
      "tags": [
        "Exploit",
        "Mitigation",
        "Vendor Advisory"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://www.rfc-editor.org/rfc/rfc7515.html#section-4.1.11",
      "tags": [
        "Technical Description"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/nearform/fast-jwt/security/advisories/GHSA-hm7r-c7qw-ghp6",
      "tags": [
        "Exploit",
        "Mitigation",
        "Vendor Advisory"
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-345"
        },
        {
          "lang": "en",
          "value": "CWE-636"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "fast-jwt provides fast JSON Web Token (JWT) implementation. In 6.1.0 and earlier, fast-jwt does not validate the crit (Critical) Header Parameter defined in RFC 7515 §4.1.11. When a JWS token contains a crit array listing extensions that fast-jwt does not understand, the library accepts the token instead of rejecting it. This violates the MUST requirement in the RFC."
    }
  ],
  "lastModified": "2026-06-17T10:40:00.837",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:nearform:fast-jwt:*:*:*:*:*:node.js:*:*",
              "vulnerable": true,
              "matchCriteriaId": "FD2BA255-333A-4CF2-9B8E-C685DF7A11A9",
              "versionEndExcluding": "6.2.0"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "security-advisories@github.com"
}