[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.
CVE-2026-8161
HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.5%, top 63% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, nvd
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EPSS
- 37.7%
- KEV
- Not listed
Published
May 12, 2026
Last Modified
May 13, 2026
Advisory Details (2)
Auto-updated May 12, 2026Patch available. Sources: github.
github Patch Available
multiparty vulnerable to Denial of Service via Prototype Pollution leading to Uncaught Exception · Advisory · pillarjs/multiparty · GitHub
https://github.com/pillarjs/multiparty/security/advisories/GHSA-qxch-whhj-8956generic
Security Advisories | OpenJS Foundation CVE Numbering Authority
https://cna.openjsf.org/security-advisories.htmlVendor Advisories for CVE-2026-8161(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
npm(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| multiparty | — | 4.3.0 | — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Frequently asked(5)
What is CVE-2026-8161?
CVE-2026-8161 is a high vulnerability published on May 12, 2026. [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…
When was CVE-2026-8161 disclosed?
CVE-2026-8161 was first published in the National Vulnerability Database on May 12, 2026, with the most recent update on May 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-8161 actively exploited?
CVE-2026-8161 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 37.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-8161?
CVE-2026-8161 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-8161?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8161, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-8161
Is Your Infrastructure Affected by CVE-2026-8161?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.