Vulnerability · Published May 4, 2026 · Assigned by GitHub_M
CVE-2026-42231n8n: Prototype Pollution in XML Webhook Body Parser Leads to RCE
Critical 9.4
In plain English
A critical-severity prototype pollution in n8n from n8n-io. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 58% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | n8n | 1.123.32 | GHSA-q5f4-99jv-pgg5 |
| npm | n8n | 2.18.1 | GHSA-q5f4-99jv-pgg5 |
| npm | n8n | 2.17.4 | GHSA-q5f4-99jv-pgg5 |
Affected products (as reported)
Weakness: CWE-1321 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
References
- https://github.com/n8n-io/n8n/security/advisories/GHSA-q5f4-99jv-pgg5 x_refsource_CONFIRM