Riskcovery

CVE-2026-8161

multiparty vulnerable to Denial of Service via Prototype Pollution leading to Uncaught Exception

State
Published
Severity
7.5 High
Published
May 12, 2026
Updated
May 12, 2026
Reserved
May 8, 2026

Read the record on cve.org

Description

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.

Scores

CVSSScoreVectorSource
3.17.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hopenjs

Weaknesses

  • CWE-248 Uncaught Exception
  • CWE-1321 Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Affected Products

ProductVersions
multipartymultiparty
  • 4.2.3 and earlierAffected
  • 4.3.0Not affected

References

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