« Volver al listado

CVE-2026-18248

Estado: AnalizadaCrítica (9.1)—

@fastify/aws-lambda version 6.4.0 decorates each Fastify request with request.awsLambda.event and request.awsLambda.context, values that applications are documented to use for authorization decisions such as reading API Gateway authorizer claims. In the default configuration, the getter that populates this decoration reads the client-controlled x-apigateway-event and x-apigateway-context HTTP headers before falling back to the trusted internal request token, and those reserved headers are not stripped from the incoming event.

Leer descripción completaMostrar menos

An unauthenticated attacker who can set a single HTTP header can therefore forge the entire Lambda proxy event, including the authorizer context, and override the genuine one. This results in a full authentication and authorization bypass and privilege escalation for any application that trusts request.awsLambda.event for identity or access control. Only version 6.4.0 is affected. Patches: upgrade to @fastify/aws-lambda 6.4.1, which resolves the decoration only through the internal per-invocation token and strips the reserved headers before the request is processed.

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.

AV:N/PR:N permite acceso remoto sin privilegios (T1190). El atacante forja headers HTTP para falsificar identidad y autorización (T1078), escalando a admin mediante bypass de controles de acceso (T1068).

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 ManagementApplication Isolation and SandboxingExploit ProtectionUpdate SoftwareApplication Developer GuidanceActive Directory Configuration

Tecnologías afectadas (1)

Fastify — Fastify/aws-lambda

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-18248",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-18248",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-08-03T19:35:01.188526Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.1,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.2,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "affectedData": [
        {
          "vendor": "@fastify/aws-lambda",
          "product": "@fastify/aws-lambda",
          "versions": [
            {
              "status": "affected",
              "version": "6.4.0",
              "lessThan": "6.4.1",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.4.1",
              "versionType": "semver"
            }
          ],
          "packageURL": "pkg:npm/@fastify/aws-lambda",
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-08-03T16:16:28.247",
  "references": [
    {
      "url": "https://cna.openjsf.org/security-advisories.html",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb"
    },
    {
      "url": "https://github.com/fastify/aws-lambda-fastify/security/advisories/GHSA-m93c-jj3f-68ph",
      "tags": [
        "Mitigation",
        "Vendor Advisory"
      ],
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "description": [
        {
          "lang": "en",
          "value": "CWE-345"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "@fastify/aws-lambda version 6.4.0 decorates each Fastify request with request.awsLambda.event and request.awsLambda.context, values that applications are documented to use for authorization decisions such as reading API Gateway authorizer claims. In the default configuration, the getter that populates this decoration reads the client-controlled x-apigateway-event and x-apigateway-context HTTP headers before falling back to the trusted internal request token, and those reserved headers are not stripped from the incoming event. An unauthenticated attacker who can set a single HTTP header can therefore forge the entire Lambda proxy event, including the authorizer context, and override the genuine one. This results in a full authentication and authorization bypass and privilege escalation for any application that trusts request.awsLambda.event for identity or access control. Only version 6.4.0 is affected. Patches: upgrade to @fastify/aws-lambda 6.4.1, which resolves the decoration only through the internal per-invocation token and strips the reserved headers before the request is processed."
    }
  ],
  "lastModified": "2026-09-04T13:44:16.757",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:fastify:fastify\\/aws-lambda:6.4.0:*:*:*:*:node.js:*:*",
              "vulnerable": true,
              "matchCriteriaId": "D6C7B2A3-A135-4087-B0F4-85C656A57576"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "ce714d77-add3-4f53-aff5-83d477b104bb"
}