GitHub Advisoryadvisory · npm
GHSA-qxch-whhj-8956 multiparty: Denial of Service via Prototype Pollution leads to Uncaught Exception
HIGH
Official page ↗
- Aliases
- CVE-2026-8161
- Ecosystem
- npm
- Packages
- multiparty
- Severity
- High
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-1321, CWE-248
- Reviewed
- 2026-05-18
Affected packages
• npm multiparty: < 4.3.0 → fixed in 4.3.0
Description
Impact
[email protected] and lower versions are vulnerable to denial of service via uncaught exception. By sending a `multipart/form-data` request with a field name that collides with an inherited `Object.prototype` property (e.g., `__proto__`, `constructor`, `toString`), the parser invokes `.push()` on the inherited prototype value rather than an array, throwing a `TypeError` that propagates as an uncaught exception and crashes the process. Any service accepting multipart uploads via multiparty is affected.
Patches
Users should upgrade to [email protected] or higher.
Workarounds
None.
Related
Alias · CVE (1)
- CVE-2026-8161 [email protected] and lower versions are vulnerable to denial of service via uncaught exception. vulnerability