parse-nested-form-data is a tiny node module for parsing FormData by name into objects and arrays. Prior to version 1.0.1, parseFormData() walks bracket and dot-notation FormData field names into nested objects without filtering reserved property keys. A single FormData field whose name begins with __proto__, or contains .__proto__. mid-path, causes the parser to traverse onto Object.prototype and assign properties there, polluting the prototype chain of every plain object in the running process. This issue has been patched in version 1.0.1.
History

Mon, 01 Jun 2026 19:00:00 +0000

Type Values Removed Values Added
Description parse-nested-form-data is a tiny node module for parsing FormData by name into objects and arrays. Prior to version 1.0.1, parseFormData() walks bracket and dot-notation FormData field names into nested objects without filtering reserved property keys. A single FormData field whose name begins with __proto__, or contains .__proto__. mid-path, causes the parser to traverse onto Object.prototype and assign properties there, polluting the prototype chain of every plain object in the running process. This issue has been patched in version 1.0.1.
Title Prototype Pollution in parse-nested-form-data via `__proto__` in FormData field names
Weaknesses CWE-1321
References
Metrics cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-06-01T17:20:34.772Z

Reserved: 2026-05-11T20:14:43.202Z

Link: CVE-2026-45302

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-06-01T19:16:51.113

Modified: 2026-06-01T19:16:51.113

Link: CVE-2026-45302

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-01T21:15:15Z