Insufficient validation of credential references in the inline workflow JSON of nodes that execute inline sub-workflows, such as the Workflow Tool node, allows a shared-workflow editor or any user interacting via the REST API, Public API, or MCP to persist a node referencing a credential they do not own. If the workflow is executed by an identity that possesses the referenced credential, the inline sub-workflow can resolve the secret and transmit it to an external endpoint controlled by an attacker, leading to credential exfiltration.