CVE-2026-42231 n8n: Prototype Pollution in XML Webhook Body Parser Leads to RCE

Critical 9.4 Published Updated

Authenticated users can achieve remote code execution on the n8n host by exploiting prototype pollution in the XML webhook parser.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2026-42231?

CVE-2026-42231 is a critical code injection vulnerability in N8n N8n, published on 4 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

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.

Weakness: CWE-1321

Which versions are affected by CVE-2026-42231?

6 open source packages ship an affected version, including n8n. It affects 1 product.

PackageAffectedFixed in
n8n npmAll versions1.123.32
n8n npmAll versions1.123.32
n8n npmFrom 2.17.02.17.4
n8n npmFrom 2.17.02.17.4
n8n npmFrom 2.18.02.18.1
n8n npmFrom 2.18.02.18.1

Products include N8n N8n.

How do I fix CVE-2026-42231?

Upgrade n8n to a fixed version for your release line: 1.123.32, 2.17.4 or 2.18.1.

Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.

Is CVE-2026-42231 being exploited?

There is no known exploitation of CVE-2026-42231 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

All N8n N8n vulnerabilities

Sources

Also known as GHSA-q5f4-99jv-pgg5.

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