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

n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the OpenAI Chat Model node enforced credential allowed-domain restrictions for normal calls but not for the model-search dropdown. A workflow editor could set options.baseURL to an arbitrary host and make the searchModels path send the openAiApi credential there. The affected implementation is packages/@n8n/nodes-langchain/nodes/llms/LMChatOpenAi/methods/loadModels.ts, which omitted assertOpenAiCredentialAllowsUrl. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.

n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the OpenAI Chat Model node enforced credential allowed-domain restrictions for normal calls but not for the model-search dropdown. A workflow editor could set options.baseURL to an arbitrary host and make the searchModels path send the openAiApi credential there. The affected implementation is packages/@n8n/nodes-langchain/nodes/llms/LMChatOpenAi/methods/loadModels.ts, which omitted assertOpenAiCredentialAllowsUrl. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.

n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the OpenAI Chat Model node enforced credential allowed-domain restrictions for normal calls but not for the model-search dropdown. A workflow editor could set options.baseURL to an arbitrary host and make the searchModels path send the openAiApi credential there. The affected implementation is packages/@n8n/nodes-langchain/nodes/llms/LMChatOpenAi/methods/loadModels.ts, which omitted assertOpenAiCredentialAllowsUrl. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.

## 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.