{"cve":"CVE-2021-43801","nvd":{"published":"2021-12-13T20:15:07.577","modified":"2026-06-17T04:11:27.953","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-754"],"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","https://github.com/mercurius-js/mercurius/issues/677","https://github.com/mercurius-js/mercurius/pull/678/commits/732b2f895312da8deadd7b173dcd2d141d54b223"],"products":["mercurius_project:mercurius"],"source":"nvd","synced_at":"2026-10-19T21:25:41.256909649+00:00"},"epss":{"cve":"CVE-2021-43801","score":0.01572,"percentile":0.75404,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-273r-rm8g-7f3x","url":"https://osv.dev/vulnerability/GHSA-273r-rm8g-7f3x","summary":"Uncaught Exception in mercurius","modified":"2026-07-08T06:28:22.772382774Z","packages":[{"ecosystem":"npm","name":"mercurius","purl":"pkg:npm/mercurius","ranges":[">=8.10.0 <8.11.2"],"fixed":["8.11.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}