---
id: CVE-2026-45302
title: >-
  parse-nested-form-data is a tiny node module for parsing FormData by name into
  objects and arrays
summary: >-
  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…
severity: high
cvss: 8.2
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L'
cwe:
  - CWE-1321
published: '2026-06-01'
updated: '2026-07-22'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-45302'
references:
  - url: >-
      https://github.com/milamer/parse-nested-form-data/commit/527ad58eb486e32438f7198fb88315c20449d792
    label: security-advisories@github.com
  - url: 'https://github.com/milamer/parse-nested-form-data/releases/tag/v1.0.1'
    label: security-advisories@github.com
  - url: >-
      https://github.com/milamer/parse-nested-form-data/security/advisories/GHSA-xp7r-j8r6-j9h3
    label: security-advisories@github.com
  - url: >-
      https://github.com/milamer/parse-nested-form-data/security/advisories/GHSA-xp7r-j8r6-j9h3
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00315
epssPercentile: 0.24675
ingestedAt: '2026-07-23T07:14:46.452Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.