n8n: Domain-Restriction Bypass via Unguarded Model-Search Endpoint in OpenAI Chat Model Node

Impact

The OpenAI Chat Model node checked a custom base URL against the credential's allowed-domains configuration before sending a request, but the model-search dropdown did not. A request setting options.baseURL on that path reached an arbitrary host with the credential attached, so the domain restriction an administrator configured did not hold for every route the node offered. The patch routes every OpenAI call site, including model listing, through one shared allowed-domains check.

Patches

The issue has been fixed in n8n versions 1.123.76, 2.37.7, and 2.38.2. 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.
• Audit all domain-restricted openAiApi credentials and revoke use-only shares granted to untrusted users.
• Rotate any openAiApi credential secrets that may have been exposed and review downstream OpenAI account activity for unexpected usage.

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