{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "1.35.0"
              },
              {
                "fixed": "1.35.13"
              },
              {
                "introduced": "1.36.0"
              },
              {
                "fixed": "1.36.9"
              },
              {
                "introduced": "1.37.0"
              },
              {
                "fixed": "1.37.5"
              },
              {
                "introduced": "1.38.0"
              },
              {
                "fixed": "1.38.3"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "84305a6cb64bd55aaf606bdd53de7cd6080427a1"
            },
            {
              "fixed": "adb998f2875986005be294d10231a9c9a497e30d"
            },
            {
              "introduced": "63ee0dc79dce88117c6bd2df5a742f8eb67ea980"
            },
            {
              "fixed": "57198c441a298a75097c690726d90974549a9778"
            },
            {
              "introduced": "6d9bb7d9a85d616b220d1f8fe67b61f82bbdb8d3"
            },
            {
              "fixed": "f97695a50e11f5ff6719e129a466bf9204b64a7f"
            },
            {
              "introduced": "f1dd21b16c244bda00edfb5ffce577e12d0d2ec2"
            },
            {
              "fixed": "0ebfcfe5b0484b89ca85b761da9e05ce75dbda8d"
            }
          ],
          "repo": "https://github.com/envoyproxy/envoy",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-8phg-2h2q-jgxf"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-444"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48743.json"
  },
  "details": "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.",
  "id": "CVE-2026-48743",
  "modified": "2026-07-08T05:37:02.949279188Z",
  "published": "2026-06-26T17:34:22.470Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48743.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-8phg-2h2q-jgxf"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48743"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Envoy: HTTP/3 to HTTP/1 request smuggling via headers-only request with nonzero Content-Length"
}