n8n: Privilege Escalation and Code Execution via Full Public API Key Scope Assignment to Token Exchange JWTs

Impact

JWTs issued through the Token Exchange module were assigned all Public API key scopes, regardless of the acting user's actual role. A low-privileged user who could obtain a valid external JWT trusted by a configured issuer could therefore use the resulting access token to invoke administrator-only Public API operations, such as role escalation, user creation, and user deletion.

The issue only affects instances where the Token Exchange feature and the Public API are enabled (N8N_TOKEN_EXCHANGE_ENABLED=true, N8N_ENV_FEAT_TOKEN_EXCHANGE=true) and the attacker can obtain an external JWT accepted by a configured trusted key. Role escalation additionally requires an Advanced Permissions license; Community Package installation additionally requires N8N_COMMUNITY_PACKAGES_ENABLED=true and N8N_UNVERIFIED_PACKAGES_ENABLED=true.

Patches

The issue has been fixed in n8n version 2.30.1 and 2.29.8. 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:

• Disable the Token Exchange feature by setting N8N_TOKEN_EXCHANGE_ENABLED=false or N8N_ENV_FEAT_TOKEN_EXCHANGE=false.
• If Token Exchange cannot be disabled, restrict Public API access at the network level to trusted clients only.
• Disable unverified Community Package installation by setting N8N_UNVERIFIED_PACKAGES_ENABLED=false to eliminate the code execution path.

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