CVE-2026-8161 — multiparty vulnerable to Denial of Service via Prototype Pollution leading to Uncaught Exception
multiparty@4.2.3 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 …
Published: 2026-05-12 · CVSS: 7.5 · CVSS 3.1
multiparty@4.2.3 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 such as __proto__, constructor, or 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. Impact: any service accepting multipart uploads via multiparty is affected. Workarounds: none. Upgrade to multiparty@4.3.0 or higher.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7