CVE-2026-45302

Prototype Pollution in parse-nested-form-data via `__proto__` in FormData field names

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.

Affected

milamer · parse-nested-form-data

CVSS v3.1 GITHUB

8.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L

EPSS

0.56% chance of exploitation in the next 30 days, 46th percentile

Published

2026-06-01

Updated

2026-06-02

Proof-of-concept exploits (1)

• advisories/GHSA-xp7r-j8r6-j9h3

References

• CVE Record
• NVD entry