Summary
n8n: Prototype Pollution via Workflow Credentials Leads to Unauthenticated User and Project Enumeration
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
- Restrict workflow creation and editing permissions to fully trusted users only.
- Restrict network access to the n8n instance to trusted users only.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Impact
An authenticated user with the default workflow:create permission could pollute Object.prototype through a crafted workflow saved, updated, or imported via the workflow API. This can be leveraged to bypass authentication, allowing unauthenticated requests to be treated as a privileged user and exposing endpoints such as the user and project listings. As a result, every account's personal data (email, role, MFA status) and all projects on the instance may be disclosed to unauthenticated callers. The pollution can also corrupt global state, making parts of the instance unresponsive until restarted.
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 1.123.61, 2.27.4, and 2.28.1. Users should upgrade to one of these versions or later to remediate the vulnerability.
Frequently Asked Questions
- What is CVE-2026-59206? CVE-2026-59206 is a high-severity security vulnerability in n8n (npm), affecting versions < 1.123.61. It is fixed in 1.123.61, 2.28.1, 2.27.4.
- Which versions of n8n are affected by CVE-2026-59206? n8n (npm) versions < 1.123.61 is affected.
- Is there a fix for CVE-2026-59206? Yes. CVE-2026-59206 is fixed in 1.123.61, 2.28.1, 2.27.4. Upgrade to this version or later.
- Is CVE-2026-59206 exploitable, and should I be worried? Whether CVE-2026-59206 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-2026-59206 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-2026-59206?
- Upgrade
n8nto 1.123.61 or later - Upgrade
n8nto 2.28.1 or later - Upgrade
n8nto 2.27.4 or later
- Upgrade