CVE-2026-46510: Kaspernj Form-Data-Objectizer

High severity, CVSS 8.2. EPSS: 0.5% chance of exploitation in the next 30 days.

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.

Affected products

• Kaspernj Form-Data-Objectizer: before 1.0.1 (fixed in 1.0.1)

Published 2026-05-29. Last modified 2026-07-21.