Summary
n8n: Cross-Issuer Token Exchange Account Binding via Subject-Only Identity Resolution
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
- If multiple trusted issuers are not required, reduce the token exchange configuration to a single trusted issuer.
- Disable the token exchange feature entirely if it is not in active use.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Impact
When an n8n instance is configured with more than one trusted token-exchange issuer, external identities are resolved to local accounts using only the JWT sub claim, ignoring the issuer (iss). As a result, two different issuers that emit the same subject value map to the same local account.
An attacker who can obtain a valid token from one trusted issuer with a sub matching a victim registered under a different issuer can authenticate as that victim and access their account.
This issue only affects instances where the token exchange feature is enabled and more than one trusted external issuer is configured.
The application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.
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 version 2.28.1. Users should upgrade to this version or later to remediate the vulnerability.
Frequently Asked Questions
- What is CVE-2026-59208? CVE-2026-59208 is a high-severity improper authentication vulnerability in n8n (npm), affecting versions >= 2.28.0, < 2.28.1. It is fixed in 2.28.1, 2.27.4. The application does not adequately verify the identity of a user, device, or process before granting access.
- Which versions of n8n are affected by CVE-2026-59208? n8n (npm) versions >= 2.28.0, < 2.28.1 is affected.
- Is there a fix for CVE-2026-59208? Yes. CVE-2026-59208 is fixed in 2.28.1, 2.27.4. Upgrade to this version or later.
- Is CVE-2026-59208 exploitable, and should I be worried? Whether CVE-2026-59208 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-2026-59208 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-2026-59208?
- Upgrade
n8nto 2.28.1 or later - Upgrade
n8nto 2.27.4 or later
- Upgrade