CVE-2026-8161 | multiparty vulnerable to Denial of Service via Prototype Pollution leading to Uncaught Exception

[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 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 [email protected] or higher.

Published: 2026-05-12 Last update: 2026-05-13 Assigner: ce714d77-add3-4f53-aff5-83d477b104bb Source: ce714d77-add3-4f53-aff5-83d477b104bb
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-8161 is rated Low Risk (31.4/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-8161

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-22 0.05% 0.02% -0.04%
2 2026-05-18 0.04% 0.05% +0.01%
3 2026-05-12 — 0.04% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-8161

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 ce714d77-add3-4f53-aff5-83d477b104bb

Weakness enumeration for CVE-2026-8161

GitHub Security Advisory for CVE-2026-8161

GHSA-qxch-whhj-8956 · Severity: high · Ecosystem: npm — multiparty: Denial of Service via Prototype Pollution leads to Uncaught Exception

OS Trackers for CVE-2026-8161

vendor priority summary link
debian not yet assigned CVE-2026-8161 not yet assigned priority: Debian including 1 source packages (node-multiparty), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2026-8161

Affected software / configurations for CVE-2026-8161

Vendor Product Version Raw CPE
pillarjs multiparty < 4.3.0 cpe:2.3:a:pillarjs:multiparty:*:*:*:*:*:node.js:*:*

References for CVE-2026-8161

cvelogic Threat Intelligence