CVE-2026-48743

{
  "id": "CVE-2026-48743",
  "sourceIdentifier": "[email protected]",
  "published": "2026-06-26T18:17:00.173",
  "lastModified": "2026-10-25T17:10:00.197",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, Envoy can translate a downstream HTTP/3 request that is complete at the transport layer (HEADERS with FIN / headers-only close) but still carries a nonzero Content-Length into a complete upstream HTTP/1 request with unresolved body debt. In an HTTP/1 upstream deployment where the origin replies before reading the declared body and keeps the connection reusable, the beginning of the next Envoy-generated upstream request can be consumed as the first request's body. The remaining bytes are then parsed by the origin as a new HTTP/1 request. This was reproduced as a route-bypass/desync: direct /pwn was denied by Envoy, but the second downstream H3 stream received the response for backend-parsed GET /pwn HTTP/1.1. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1."
    },
    {
      "lang": "es",
      "value": "Envoy es un proxy de borde y de servicio de código abierto diseñado para aplicaciones nativas de la nube. Antes de 1.35.11, 1.36.7, 1.37.3 y 1.38.1, Envoy puede traducir una solicitud HTTP/3 descendente que está completa en la capa de transporte (HEADERS con FIN / cierre solo de encabezados) pero que aún lleva una Content-Length distinta de cero en una solicitud HTTP/1 ascendente completa con deuda de cuerpo no resuelta. En una implementación ascendente HTTP/1 donde el origen responde antes de leer el cuerpo declarado y mantiene la conexión reutilizable, el comienzo de la siguiente solicitud ascendente generada por Envoy puede ser consumido como el cuerpo de la primera solicitud. Los bytes restantes son entonces analizados por el origen como una nueva solicitud HTTP/1. Esto se reprodujo como un bypass de ruta/desincronización: el /pwn directo fue denegado por Envoy, pero el segundo flujo H3 descendente recibió la respuesta para el GET /pwn HTTP/1.1 analizado por el backend. Esta vulnerabilidad está corregida en 1.35.11, 1.36.7, 1.37.3 y 1.38.1."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "envoyproxy",
          "product": "envoy",
          "versions": [
            {
              "version": ">= 1.38.0, < 1.38.1",
              "status": "affected"
            },
            {
              "version": ">= 1.37.0, < 1.37.3",
              "status": "affected"
            },
            {
              "version": ">= 1.36.0, < 1.36.7",
              "status": "affected"
            },
            {
              "version": ">= 1.35.0, < 1.35.11",
              "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:C/C:L/I:H/A:N",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "CHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "HIGH",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 4.7
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-06-29T15:04:55.378026Z",
          "id": "CVE-2026-48743",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-444"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "1.35.0",
              "versionEndExcluding": "1.35.13",
              "matchCriteriaId": "AB149324-8F14-48A5-ABC1-B4764A0BC33B"
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              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
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  "references": [
    {
      "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-8phg-2h2q-jgxf",
      "source": "[email protected]",
      "tags": [
        "Exploit",
        "Vendor Advisory",
        "Mitigation"
      ]
    },
    {
      "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-8phg-2h2q-jgxf",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "Exploit",
        "Vendor Advisory",
        "Mitigation"
      ]
    }
  ]
}