CVE-2026-8161

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.

Score

CVSS 3.1 7.5 High

Status

Analyzed - ce714d77-add3-4f53-aff5-83d477b104bb

Published

2026-05-12

Last modified

2026-05-12

Weaknesses

CWE-1321, CWE-248

Affected products

• Multiparty (Multiparty)
• Multiparty (Pillarjs)

References

• https://cna.openjsf.org/security-advisories.html
• https://github.com/pillarjs/multiparty/security/advisories/GHSA-qxch-whhj-8956