AI agent vulnerability · n8n

CVE-2026-56358: n8n has a Stored XSS Vulnerability in its Form Trigger

mediumCVSS 4.0 5.1 · 3.1 5.4GHSA-q4fm-pjq6-m63g

Impact An authenticated user with permission to create or modify workflows could exploit a flaw in the Form Trigger node's CSS sanitization to store a cross-site scripting (XSS) payload. The injected script executes persistently for every visitor of the published form, enabling form submission hijacking and phishing.

Published Mar 27, 2026 · Updated Jul 20, 2026

Affected packages

n8n

Ecosystem: npm
Affected: >= 2.0.0-rc.0, < 2.11.2
Fixed in: 2.11.2
Check: npm ls n8n

n8n

Ecosystem: npm
Affected: < 1.123.25
Fixed in: 1.123.25
Check: npm ls n8n

Advisory details

From the GitHub Advisory Database (CC BY 4.0).

Impact

An authenticated user with permission to create or modify workflows could exploit a flaw in the Form Trigger node's CSS sanitization to store a cross-site scripting (XSS) payload. The injected script executes persistently for every visitor of the published form, enabling form submission hijacking and phishing. The existing Content Security Policy prevents direct n8n session cookie theft but does not prevent script execution or form action manipulation.

Patches

The issue has been fixed in n8n versions 2.12.0, 2.11.2, and 1.123.25. Users should upgrade to one of these versions or later to remediate the vulnerability.

Workarounds

If upgrading is not immediately possible, administrators should consider the following temporary mitigations:

Limit workflow creation and editing permissions to fully trusted users only.
Disable the Form Trigger node by adding n8n-nodes-base.formTrigger to the NODES_EXCLUDE environment variable.

These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

Credited to tr4ce-ju.

References

How this page is made: the data panel comes from the GitHub Advisory Database, CISA’s KEV catalog, the NVD and FIRST EPSS, and updates twice a day. No analysis has been written for this entry yet. Methodology

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