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Luu, T.J.

GHSA-9cmh-xcqm-5hqr: n8n: Cross-Tenant Module-Cache Poisoning in the JS Task Runner

mediumvulnerability

security

Source: GitHub Advisory DatabaseJuly 22, 2026

Summary

n8n's JavaScript task runner had a vulnerability where all users' Code nodes (executable code blocks within n8n workflows) shared the same module cache (a storage area for reusable code libraries), allowing one user to poison it (corrupt or modify cached code) and affect other users' executions. This is a cross-tenant isolation break (where data from different users isn't properly separated) but not a sandbox escape (breaking out of a restricted environment) or RCE (remote code execution, where attackers run commands on systems they don't own).

Solution / Mitigation

Upgrade to n8n version 1.123.67, 2.31.5, or 2.32.1 or later. If upgrading is not immediately possible, administrators can temporarily: restrict 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` environment variables; or use external runner mode with a dedicated runner per user or project. The source notes these workarounds do not fully remediate the risk and should only be short-term measures.