CVE-2026-46510

Prototype pollution in form-data-objectizer via bracket-notation form keys

Published May 29, 2026 CVSS 3.1 · 8.2 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-m2hg-wjq3-28wq form-data-objectizer: Prototype pollution in form-data-objectizer via bracket-notation form keys
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Kaspernj
Kaspernj form-data-objectizer
Vendors & Products Kaspernj
Kaspernj form-data-objectizer
Type Values Removed Values Added
Description 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.
Title Prototype pollution in form-data-objectizer via bracket-notation form keys
Weaknesses CWE-1321
References
Metrics cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jun 2, 2026, 1:28 AM
Reserved
May 14, 2026, 7:12 PM
Status
Deferred
Published
May 29, 2026, 2:16 PM
Modified
Jul 21, 2026, 12:10 PM