CVE-2026-42231

HIGH LAB

n8n: Prototype Pollution in XML Webhook Body Parser Leads to RCE

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-42231. PoCs published by rudSarkar.

AI-analyzed exploit summary This repository contains a functional exploit for CVE-2026-42231, demonstrating XML prototype pollution in n8n leading to RCE via Git node manipulation. The PoC includes detailed technical analysis, Docker setup, and exploit scripts.

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.

Exploits (1)

nomisec WORKING POC
by rudSarkar · poc
https://github.com/rudSarkar/CVE-2026-42231

This repository contains a functional exploit for CVE-2026-42231, demonstrating XML prototype pollution in n8n leading to RCE via Git node manipulation. The PoC includes detailed technical analysis, Docker setup, and exploit scripts.

Classification
Working Poc 100%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: n8n < 1.123.32 / < 2.17.4 / < 2.18.1
No auth needed
Prerequisites: public Webhook trigger with XML content type · Git node performing SSH operations · n8n version < 1.123.32
devstral-2 · analyzed May 07, 2026 Full analysis →

References (1)

Core 1
Core References

Scores

CVSS v3 8.8
EPSS 0.0030
EPSS Percentile 53.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Lab Environment

COMMUNITY
Community Lab
docker pull n8nio/n8n:1.123.22
docker pull n8n-proto-pollution-poc:latest

Details

CWE
CWE-1321
Status published
Products (8)
n8n/n8n 2.18.0
n8n/n8n < 1.123.32
n8n-io/n8n < 1.123.32
n8n-io/n8n >= 2.17.0, < 2.17.4
n8n-io/n8n >= 2.18.0, < 2.18.1
npm/n8n 0 - 1.123.32npm
npm/n8n 2.17.0 - 2.17.4npm
npm/n8n 2.18.0 - 2.18.1npm
Published May 04, 2026
Tracked Since May 05, 2026