{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "B303FFFE-9973-4E7E-8A8C-DE847B725534",
              "versionEndExcluding": "1.33.13",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "4419A82D-995F-4DD0-BAE1-3825791245D3",
              "versionEndExcluding": "1.34.11",
              "versionStartIncluding": "1.34.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "C50E067C-AE0D-4B14-A442-53603039EFCD",
              "versionEndExcluding": "1.35.7",
              "versionStartIncluding": "1.35.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "B39C3DF2-E73F-4B66-9504-C24E329ACB54",
              "versionEndExcluding": "1.36.3",
              "versionStartIncluding": "1.36.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, when Envoy is configured in TCP proxy mode to handle CONNECT requests, it accepts client data before issuing a 2xx response and forwards that data to the upstream TCP connection. If a forwarding proxy upstream from Envoy then responds with a non-2xx status, this can cause a de-synchronized CONNECT tunnel state. By default Envoy continues to allow early CONNECT data to avoid disrupting existing deployments. The envoy.reloadable_features.reject_early_connect_data runtime flag can be set to reject CONNECT requests that send data before a 2xx response when intermediaries upstream from Envoy may reject establishment of a CONNECT tunnel."
    },
    {
      "lang": "es",
      "value": "Envoy es un proxy de borde/intermedio/servicio de alto rendimiento. En las versiones 1.33.12, 1.34.10, 1.35.6, 1.36.2 y anteriores, cuando Envoy est\u00e1 configurado en modo proxy TCP para manejar solicitudes CONNECT, acepta datos del cliente antes de emitir una respuesta 2xx y reenv\u00eda esos datos a la conexi\u00f3n TCP ascendente. Si un proxy de reenv\u00edo ascendente de Envoy responde con un estado que no es 2xx, esto puede causar un estado de t\u00fanel CONNECT desincronizado. Por defecto, Envoy contin\u00faa permitiendo datos CONNECT tempranos para evitar interrumpir las implementaciones existentes. El indicador de tiempo de ejecuci\u00f3n \u0027envoy.reloadable_features.reject_early_connect_data\u0027 puede configurarse para rechazar solicitudes CONNECT que env\u00edan datos antes de una respuesta 2xx cuando los intermediarios ascendentes de Envoy pueden rechazar el establecimiento de un t\u00fanel CONNECT."
    }
  ],
  "id": "CVE-2025-64763",
  "lastModified": "2025-12-05T16:52:24.367",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 3.7,
          "baseSeverity": "LOW",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2025-12-03T18:15:47.037",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-rj35-4m94-77jh"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-693"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}