CVE-2026-45302: Milamer Parse-Nested-Form-Data

High severity, CVSS 8.2. EPSS: 0.6% chance of exploitation in the next 30 days.

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 products

• Milamer Parse-Nested-Form-Data: before 1.0.1 (fixed in 1.0.1)

Published 2026-06-01. Last modified 2026-07-22.