Prototype Pollution in N8n

CVE-2026-42231

n8n is an open source workflow automation platform. Prior to versions 1.123.32, 2.17.4, and 2.18.1, a flaw in the xml2js library used to parse XML request bodies in n8n's webhook handler allowed prototype pollution via a crafted XML payload. An authenticated user with permission to create or modify workflows could exploit this to pollute the JavaScript object prototype and, by chaining the pollution with the Git node's SSH operations, achieve remote code execution on the n8n host. This issue has been patched in versions 1.123.32, 2.17.4, and 2.18.1.

Vulnerability class: Prototype Pollution

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.008 (53.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 53.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-42231: held from 0.009 to 0.008.

EPSS over last 30 days · oldest: 0.009 · newest: 0.008 · change: -0.001

Affected products

  • N8n — versions 2.18.0
  • N8n-Io N8n — versions < 1.123.32, >= 2.17.0, < 2.17.4, >= 2.18.0, < 2.18.1

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-42231?
CVE-2026-42231 is a high-severity vulnerability in N8n, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 8.8/10. Published 2026-05-04.
How severe is CVE-2026-42231?
High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2026-42231 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.