Summary
n8n: DOM-Based XSS via Unsandboxed iframe srcdoc in HTML Preview
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
- Restrict n8n instance access to fully trusted users only.
- Set the
N8N_CONTENT_SECURITY_POLICYenvironment variable to a policy that blocks inline scripts. - Avoid exposing workflows that render externally-controlled input into the HTML node or binary HTML preview to untrusted users.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Impact
The HTML preview renders execution output into an iframe srcdoc without sandbox, so a sanitizer bypass lets injected script run same-origin as the editor. When a victim opens the preview, it can call authenticated APIs with their session. An account with global:member privileges can exploit it.
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.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
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. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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The issue has been fixed in n8n versions 1.123.64, 2.29.8, and 2.30.1. Users should upgrade to one of these versions or later to remediate the vulnerability.
Frequently Asked Questions
- What is CVE-2026-65597? CVE-2026-65597 is a high-severity cross-site scripting (XSS) vulnerability in n8n (npm), affecting versions < 1.123.64. It is fixed in 1.123.64, 2.30.1, 2.29.8. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- Which versions of n8n are affected by CVE-2026-65597? n8n (npm) versions < 1.123.64 is affected.
- Is there a fix for CVE-2026-65597? Yes. CVE-2026-65597 is fixed in 1.123.64, 2.30.1, 2.29.8. Upgrade to this version or later.
- Is CVE-2026-65597 exploitable, and should I be worried? Whether CVE-2026-65597 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
- What actually determines whether CVE-2026-65597 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.
- How do I fix CVE-2026-65597?
- Upgrade
n8nto 1.123.64 or later - Upgrade
n8nto 2.30.1 or later - Upgrade
n8nto 2.29.8 or later
- Upgrade