n8n GraphQL Node Domain Restriction Bypass Leading to Credential Exfiltration

Technical Analysis

n8n allows administrators to restrict which domains a given HTTP-based credential (Header Auth, Basic Auth, Query Auth, OAuth) can be used against via the 'Allowed HTTP Request Domains' setting, intended to let credentials be safely shared with less-trusted users. The HTTP Request node enforces this allowlist, but the GraphQL node — which also consumes these credential types to make outbound HTTP calls — did not apply the same check. An authenticated user able to create or edit workflows could configure a GraphQL node to send requests to a server they control while attaching a restricted credential, causing n8n to transmit the credential (headers/auth tokens) to the attacker's endpoint. This crosses a trust boundary between the credential owner (who granted restricted, domain-scoped access) and lower-privileged workflow editors, effectively acting as a tool-layer capability that silently ignores a configured security control shared across automation nodes.

Affected Systems

n8n

Detection Signatures

• n8n audit logs showing GraphQL node executions targeting unfamiliar or external endpoints
• Credential usage against domains outside expected allowlist despite 'Allowed HTTP Request Domains' being configured
• Workflow edits introducing GraphQL nodes with attacker-controlled endpoint URLs shortly after credential sharing changes
• Unexpected outbound traffic from n8n instance to non-allowlisted domains correlated with credential-bearing requests

Remediation Steps

1. 1

   Upgrade n8n

   Update to n8n 1.123.64, 2.29.8, 2.30.1, or later, which enforce the Allowed HTTP Request Domains restriction consistently across the GraphQL node and HTTP Request node.

2. 2

   Restrict workflow editing permissions

   Until patched, limit workflow creation/editing rights to fully trusted users to reduce the risk of malicious node configuration.

3. 3

   Restrict credential sharing

   Limit sharing of domain-restricted credentials to fully trusted users only, minimizing exposure to lower-privileged accounts.

4. 4

   Audit credential and domain-restriction configurations

   Review all credentials with 'Allowed HTTP Request Domains' set and their sharing relationships for unexpected or overly broad access.

5. 5

   Monitor outbound automation traffic

   Implement network-level monitoring/egress filtering for the n8n instance to detect requests to unauthorized domains carrying credential material.