CVE-2026-45302

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data tampering.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-06-01 19:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-22 08:10 UTC Last updatedMost recent change to the record

Details

Published

2026-06-01 19:16 UTC

Last modified

2026-07-22 08:10 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-1321 · Prototype pollution

Record status

Deferred

Attack profile CVSS 3.1 · 8.2

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

Low