Security advisory

{
  "id": "f9e64cc02f988d300858f07a152949cc76f69437ccfbb1711b82c3c5cf575ec1",
  "url": "https://osv.dev/vulnerability/CVE-2019-18802",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2019-18802",
    "summary": "An issue was discovered in Envoy 1.12.0. An untrusted remote client may send an HTTP header (such as Host) with whitespace after the header content. Envoy will treat \"header-value \" as a different string from \"header-value\" so for example with the Host header \"example.com \" one could bypass \"example.com\" matchers.",
    "evidence": "osv:CVE-2019-18802",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2019-18802",
      "aliases": [
        "CVE-2019-18802",
        "GHSA-356m-vhw2-wcm4"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/envoyproxy/envoy",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "44f8c365a1f1798f0af776f6aa64279dc68f5666"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.12.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.12.1",
            "v1.12.0",
            "v1.11.0",
            "v1.10.0",
            "v1.9.0",
            "v1.8.0",
            "v1.7.0",
            "v1.6.0",
            "v1.5.0",
            "v1.4.0",
            "v1.3.0",
            "v1.2.0",
            "v1.1.0",
            "v1.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2019-18802.json"
          }
        }
      ],
      "modified": "2026-10-20T10:52:30.507134486Z",
      "provider": "osv",
      "references": [
        "https://groups.google.com/forum/#%21forum/envoy-users",
        "https://github.com/envoyproxy/envoy/commits/master",
        "https://blog.envoyproxy.io",
        "https://github.com/envoyproxy/envoy/security/advisories/GHSA-356m-vhw2-wcm4"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2019-18802",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 383675,
  "published_at": "2019-12-13T13:15:11.383+00:00"
}