CVE-2026-59208: n8n: Cross-Issuer Token Exchange Account Binding via Subject-Only Identity Resolution
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.
Patches The issue has been fixed in n8n version 2.28.1. Users should upgrade to this version or later to remediate the vulnerability.
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.
Other sources
n8n is an open source workflow automation platform. Prior to 2.27.4 and from 2.28.0 prior to 2.28.1, n8n instances configured with more than one trusted token-exchange issuer resolved external identities to local accounts using only the JWT sub claim and ignored the iss claim, allowing an attacker with a valid token from one trusted issuer and a sub matching a victim under another issuer to authenticate as that victim. This issue is fixed in versions 2.27.4 and 2.28.1.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 2.27.4 - Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 2.28.1 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.27.4 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.28.1 - Configuration
Disable the token exchange feature entirely if it is not in active use.
n8n token exchange token exchange feature = disabled - Configuration
If multiple trusted issuers are not required, reduce the token exchange configuration to a single trusted issuer (instead of multiple trusted external issuers).
n8n token exchange trusted token-exchange issuers = single trusted issuer
Event History
Frequently Asked Questions
What is the severity of CVE-2026-59208?
The severity of CVE-2026-59208 is rated at 60.
How do I fix CVE-2026-59208?
To mitigate CVE-2026-59208, upgrade to n8n version 2.28.1 or later.
What types of systems are affected by CVE-2026-59208?
CVE-2026-59208 affects n8n instances configured with more than one trusted token-exchange issuer.
What vulnerabilities does CVE-2026-59208 introduce?
CVE-2026-59208 allows attackers to exploit cross-issuer token exchange via subject-only identity resolution.
What are the implications of CVE-2026-59208 for n8n users?
n8n users vulnerable to CVE-2026-59208 may face unauthorized account access due to insecure identity resolution.