CVE-2026-46510 HIGH

CVE-2026-46510: Prototype pollution in form-data-objectizer via bracket-notation form keys

Vendor Kaspernj
Product form-data-objectizer
Weakness CWE-1321
Published May 29, 2026
Last update June 2, 2026

CVSS base score

8.2/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity High

CVSS vector

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

What the vulnerability does

01Description

form-data-objectizer converts FormData to object. Prior to 1.0.1, form-data-objectizer walks bracket-notation form keys (e.g. name[sub]) into nested objects without filtering __proto__, constructor, or prototype. A single HTTP form field whose name starts with __proto__[...] causes the library to mutate Object.prototype, which is a prototype pollution primitive of the entire Node.js process. This vulnerability is fixed in 1.0.1.

Key dates

02Disclosure timeline

May 29, 2026 CVE published
June 2, 2026 Record updated