Security advisory

{
  "id": "5fa04f18528b8332cab6089c2498e81ec88186b82608c77b9ecc3b1011c24a83",
  "url": "https://osv.dev/vulnerability/CVE-2021-43801",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-43801",
    "summary": "Mercurius is a GraphQL adapter for Fastify. Any users from Mercurius@8.10.0 to 8.11.1 are subjected to a denial of service attack by sending a malformed JSON to `/graphql` unless they are using a custom error handler. The vulnerability has been fixed in https://github.com/mercurius-js/mercurius/pull/678 and shipped as v8.11.2. As a workaround users may use a custom error handler.",
    "evidence": "osv:CVE-2021-43801",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-43801",
      "aliases": [
        "CVE-2021-43801",
        "GHSA-273r-rm8g-7f3x"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/mercurius-js/mercurius",
              "type": "GIT",
              "events": [
                {
                  "introduced": "3b861dd8c35c09568b65d8293e4206bba9a23213"
                },
                {
                  "fixed": "d34a103fd9fe3df941acdd6072c6a602d235fcbb"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:mercurius_project:mercurius:*:*:*:*:*:node.js:*:*",
                    "range": [
                      {
                        "introduced": "8.10.0"
                      },
                      {
                        "fixed": "8.11.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v8.11.1",
            "v8.11.0",
            "v8.10.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-43801.json"
          }
        }
      ],
      "modified": "2026-10-20T10:55:04.321615106Z",
      "provider": "osv",
      "references": [
        "https://github.com/mercurius-js/mercurius/issues/677",
        "https://github.com/mercurius-js/mercurius/pull/678/commits/732b2f895312da8deadd7b173dcd2d141d54b223",
        "https://github.com/mercurius-js/mercurius/security/advisories/GHSA-273r-rm8g-7f3x"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-43801",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 386824,
  "published_at": "2021-12-13T20:15:07.577+00:00"
}