Frappe: Access control bypass via REST API dot-notation fields on linked doctypes

Frappe is a full-stack web application framework written in Python and JavaScript. Prior to version 15.115.0, an access control bypass in the REST API allows a user to read data from Linked DocTypes that they are not authorized to access. When a document references another document through a Link field, the framework does not consistently enforce the linked DocType's own permissions when the record is retrieved through the REST API, so a low-privileged authenticated user can obtain fields from linked records outside their permitted scope. This issue is fixed in version 15.115.0.