{"id":"CVE-2021-23597","aliases":["GHSA-qh73-qc3p-rjv2","SNYK-JS-FASTIFYMULTIPART-2395480"],"url":"https://o3.security/vulnerability/CVE-2021-23597","summary":"Uncaught Exception in fastify-multipart","details":"### Impact\n\nThis is a bypass of CVE-2020-8136 (https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-8136).\nBy providing a `name=constructor` property it is still possible to crash the application.\nThe original fix only checks for the key `__proto__` (https://github.com/fastify/fastify-multipart/pull/116).\n\nAll users are recommended to upgrade\n\n### Patches\n\nv5.3.1 includes a patch\n \n### Workarounds\n\nNo workarounds are possible.\n\n### References\n\nRead up https://www.fastify.io/docs/latest/Guides/Prototype-Poisoning/\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [https://github.com/fastify/fastify-multipart](https://github.com/fastify/fastify-multipart)\n* Email us at [hello@matteocollina.com](mailto:hello@matteocollina.com)\n","published":"2022-02-11T17:15:08.023Z","modified":"2026-08-07T15:13:58.063819Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.0203,"percentile":0.79298,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"npm","name":"fastify-multipart","fixedVersion":"5.3.1"}],"fix":{"url":"https://github.com/fastify/fastify-multipart/commit/a70dc7059a794589bd4fe066453141fc609e6066","label":"fastify/fastify-multipart@a70dc70"},"references":[{"type":"ADVISORY","url":"https://github.com/fastify/fastify-multipart/releases/tag/v5.3.1"},{"type":"FIX","url":"https://github.com/fastify/fastify-multipart/commit/a70dc7059a794589bd4fe066453141fc609e6066"},{"type":"FIX","url":"https://snyk.io/vuln/SNYK-JS-FASTIFYMULTIPART-2395480"},{"type":"WEB","url":"https://github.com/fastify/fastify-multipart/security/advisories/GHSA-qh73-qc3p-rjv2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-23597"},{"type":"WEB","url":"https://github.com/fastify/fastify-multipart/pull/116"},{"type":"WEB","url":"https://github.com/fastify/fastify-multipart"},{"type":"WEB","url":"https://www.fastify.io/docs/latest/Guides/Prototype-Poisoning"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T15:13:58.063819Z"}}