Summary
n8n: Cross-Tenant Module-Cache Poisoning in the JS Task Runner
Advisory details
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_BUILTINandNODE_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.
References
Related vulnerabilities
All Supply chain →- HIGHCVE-2026-75975
fast-uri vulnerable to server-side request forgery via malformed IPv6 normalization
- MEDIUMCVE-2026-18504
fastify vulnerable to schema validation bypass via root primitive coercion mismatch
- MEDIUMCVE-2026-73845
CKAN MCP Server: MQA server allowlist bypass via unanchored regex (`isValidMqaServer`)
- HIGHCVE-2026-59724
Socket.IO: Engine.IO WebTransport SID DoS
- HIGHCVE-2026-55212
Pimcore: Insufficient Permission Check on Class Definition Creation Endpoint Allows Privilege Escalation
- CRITICALCVE-2026-55068
free5GC NRF nnrf-nfm lacks NF Profile input validation — enables NF Registration Poisoning with arbitrary service endpoints