CVE-2026-42231

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

State: Published
Severity: 9.4 Critical
Published: May 4, 2026
Updated: May 5, 2026
Reserved: Apr 25, 2026

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.

Scores

CVSS	Score	Vector	Source
4.0	9.4 Critical	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	GitHub_M

Weaknesses

CWE-1321 Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Affected Products

Product	Versions
n8nn8n-io	< 1.123.32Affected >= 2.17.0, < 2.17.4Affected >= 2.18.0, < 2.18.1Affected

References

https://github.com/n8n-io/n8n/security/advisories/GHSA-q5f4-99jv-pgg5

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