n8n, the workflow automation platform from n8n-io, has a flaw in its GraphQL node where the"Allowed HTTP Request Domains" restriction is not applied to HTTP-based credential types (Header Auth, Basic Auth, Query Auth, OAuth). An authenticated user who can create or edit a workflow can point the node to an attacker-controlled endpoint; the restricted credentials are then sent to that endpoint. This is a CWE-863 "Improper Restriction of Resources" situation that does not allow direct code execution or denial of service but can leak sensitive authentication data.

The vulnerability affects all n8n releases prior to 1.123.64, including the 2.29.8 and 2.30.1 builds. Only credentials that have "Allowed HTTP Request Domains" configured and that are usable by non-owner users are at risk. The GraphQL node behaves similarly to the HTTP Request node in newer releases, which correctly enforce domain restrictions.

The CVSS score of 5.1 indicates a moderate severity. The EPSS score is reported as less than 1%, implying a low likelihood of exploitation under normal circumstances; however, because it requires only an authenticated user who can edit workflows, internal users or compromised accounts can easily meet that prerequisite. The vulnerability is not listed in the CISA KEV catalog and no public exploit has been documented, but the potential to exfiltrate domain-restricted credentials poses a significant confidentiality risk to shared resources.