n8n: Microsoft SQL Node Prototype Pollution

Impact

An authenticated user with permission to create or modify workflows could achieve global prototype pollution via the Microsoft SQL node by supplying a crafted value as the table parameter. This pollutes Object.prototype process-wide for the lifetime of the n8n server process, causing application-wide validation failures and rendering the n8n instance completely non-functional until restarted.

Patches

The issue has been fixed in n8n version 2.24.0. 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:

• Limit workflow creation and editing permissions to fully trusted users only.
• Disable the Microsoft SQL node by adding n8n-nodes-base.microsoftSql to the NODES_EXCLUDE environment variable.

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