Security advisory

{
  "id": "194a17e7f015a267645e02f49143f307f3bb4ad70fbb9a82c85e439d3e67341e",
  "url": "https://osv.dev/vulnerability/CVE-2026-37236",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2026-37236",
    "summary": "grpc-gateway v2.28.0 is vulnerable to Incorrect Access Control. The application processes the X-HTTP-Method-Override header in ServeMux.ServeHTTP without restricting allowed methods. When a POST request with Content-Type application/x-www-form-urlencoded includes this header, the request method is rewritten to an arbitrary attacker-supplied value before routing. This allows bypassing method-based access controls enforced by upstream proxies or WAFs.",
    "evidence": "osv:CVE-2026-37236",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-37236",
      "aliases": [
        "CVE-2026-37236"
      ],
      "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/grpc-ecosystem/grpc-gateway",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "72123cd4f32545f6e1376873f412dcdcbcf29acc"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "fixed": "72123cd4f32545f6e1376873f412dcdcbcf29acc"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.28.0",
            "v2.27.8",
            "v2.27.7",
            "v2.26.7",
            "v2.27.6",
            "v2.27.5",
            "v2.27.4",
            "v2.27.3",
            "v2.27.2",
            "v2.27.1",
            "v2.27.0",
            "v2.26.3",
            "v2.26.2",
            "v2.26.1",
            "v2.26.0",
            "v2.25.1",
            "v2.25.0",
            "v2.24.0",
            "v2.23.0",
            "v2.22.0",
            "v2.21.0",
            "v2.20.0",
            "v2.19.1",
            "v2.19.0",
            "v2.18.1",
            "v2.18.0",
            "v2.17.1",
            "v2.17.0",
            "v2.16.2",
            "v2.16.1",
            "v2.16.0",
            "v2.15.2",
            "v2.15.1",
            "v2.15.0",
            "v2.14.0",
            "v2.13.0",
            "v2.12.0",
            "v2.11.3",
            "v2.11.2",
            "v2.11.1",
            "v2.11.0",
            "v2.10.3",
            "v2.10.2",
            "v2.10.1",
            "v2.10.0",
            "v2.9.0",
            "v2.8.0",
            "v2.7.3",
            "v2.7.2",
            "v2.7.1",
            "v2.7.0",
            "v2.6.0",
            "v2.5.0",
            "v2.4.0",
            "v2.3.0",
            "v2.2.0",
            "v2.1.0",
            "v2.0.1",
            "v2.0.0",
            "v1.15.2",
            "v1.15.1",
            "v1.15.0",
            "v1.14.8",
            "v1.14.7",
            "v2.0.0-beta.2",
            "v1.14.6",
            "v1.14.5",
            "v2.0.0-alpha.1",
            "v1.14.4",
            "v1.14.3",
            "v1.14.2",
            "v1.14.1",
            "v1.14.0",
            "v1.13.0",
            "v1.12.2",
            "v1.12.1",
            "v1.12.0",
            "v1.11.3",
            "v1.11.2",
            "v1.11.1",
            "v1.11.0",
            "v1.10.0",
            "v1.9.6",
            "v1.9.5",
            "v1.9.4",
            "v1.9.3",
            "v1.9.2",
            "v1.9.1",
            "v1.9.0",
            "v1.8.6",
            "v1.8.5",
            "v1.8.4",
            "v1.8.3",
            "v1.8.2",
            "v1.8.1",
            "v1.8.1-pre1",
            "v1.8.0",
            "v1.7.0",
            "v1.6.4",
            "v1.6.3",
            "v1.6.2",
            "v1.5.1",
            "v1.5.0",
            "v1.4.1",
            "v1.4.0",
            "v1.3.0",
            "v1.3",
            "v1.2.2",
            "v1.2.1",
            "v1.2.0",
            "v1.2.0.rc1",
            "v1.1.0",
            "v1.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-37236.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:40.342244112Z",
      "provider": "osv",
      "references": [
        "https://s00me00ne.com/cve/cve-2026-37236/",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/37xxx/CVE-2026-37236.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-37236",
        "https://github.com/grpc-ecosystem/grpc-gateway/commit/72123cd4f32545f6e1376873f412dcdcbcf29acc",
        "https://github.com/grpc-ecosystem/grpc-gateway"
      ],
      "provider_metadata": {
        "cna_assigner": "mitre",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/37xxx/CVE-2026-37236.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-37236",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 507961,
  "published_at": "2026-08-28T00:00:00+00:00"
}