CVE-2026-45302
Prototype Pollution in parse-nested-form-data via `__proto__` in FormData field names
CVSS Score
8.2
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-1321 |
| Vendor | milamer |
| Product | parse-nested-form-data |
| Published | Jun 1, 2026 |
| Last Updated | Jun 2, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
Low
Affected Versions
milamer / parse-nested-form-data
< 1.0.1