n8n: Cross-Tenant Module-Cache Poisoning in the JS Task Runner

Impact

n8n's JavaScript task runner shared one module cache across all users' Code-node executions, so a user able to run a Code node could poison a cached module and alter other users' Code-node executions on the same runner, affecting their confidentiality, integrity, or availability.

This is a cross-user isolation break within a single n8n instance. It does not constitute a sandbox escape or remote code execution. All multi-user n8n instances running the JS task runner with built-in or external modules enabled are affected.

Patches

The issue has been fixed in n8n versions 1.123.67, 2.31.5, and 2.32.1. Users should upgrade to one of these versions or later to remediate the vulnerability.

Workarounds

If upgrading is not immediately possible, administrators should consider the following temporary mitigations:

• Restrict n8n instance access to fully trusted users only.
• Disable built-in and external module access in Code nodes by unsetting NODE_FUNCTION_ALLOW_BUILTIN and NODE_FUNCTION_ALLOW_EXTERNAL, which removes the poisonable module surface.
• Use the external runner mode with a dedicated runner per user or project if your deployment supports it.

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