CVE-2026-27578

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 Webhook node by adding n8n-nodes-base.webhook to the NODES_EXCLUDE environment variable.

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

Credit

Reporters:

• @ori-ron
• @Aikido-Security
• @nil340
• Pawel Bednarz from the NATO Cyber Security Centre (NCSC)

An authenticated user with permission to create or modify workflows could inject arbitrary scripts into pages rendered by the n8n application using different techniques on various nodes (Form Trigger node, Chat Trigger node, Send & Wait node, Webhook Node, and Chat Node). Scripts injected by a malicious workflow execute in the browser of any user who visits the affected page, enabling session hijacking and account takeover.

Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.

CVE-2026-27578 has a CVSS score of 5.4 (High). The vector is network-reachable, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.123.22, 2.9.3, 2.10.1); upgrading removes the vulnerable code path.

Kodem intelligence

The issues have been fixed in n8n versions 2.10.1, 2.9.3, and 1.123.22. Users should upgrade to one of these versions or later to remediate the vulnerability.

1. What is CVE-2026-27578? CVE-2026-27578 is a high-severity cross-site scripting (XSS) vulnerability in n8n (npm), affecting versions < 1.123.22. It is fixed in 1.123.22, 2.9.3, 2.10.1. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. How severe is CVE-2026-27578? CVE-2026-27578 has a CVSS score of 5.4 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of n8n are affected by CVE-2026-27578? n8n (npm) versions < 1.123.22 is affected.
4. Is there a fix for CVE-2026-27578? Yes. CVE-2026-27578 is fixed in 1.123.22, 2.9.3, 2.10.1. Upgrade to this version or later.
5. Is CVE-2026-27578 exploitable, and should I be worried? Whether CVE-2026-27578 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-27578 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-27578?
   • Upgrade n8n to 1.123.22 or later
   • Upgrade n8n to 2.9.3 or later
   • Upgrade n8n to 2.10.1 or later