CVE-2026-8161
multiparty vulnerable to Denial of Service via Prototype Pollution leading to Uncaught Exception
HIGH 7.5EPSS 0.5%
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.
- Affected
- multiparty
- CVSS v3.1 CNA
- 7.5 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS
- 0.53% chance of exploitation in the next 30 days, 44th percentile
- Published
- 2026-05-12
Proof-of-concept exploits (1)
- Ser0n-ath/multiparty-CVE-2026-81610★ · 2026-05-11
Security advisories
- pillarjs/multiparty/security/advisories/GHSA-qxch-whhj-8956
- https://cna.openjsf.org/security-advisories.html
- advisories/GHSA-qxch-whhj-8956