An issue was discovered in OpenStack Keystone before 29.0.2. The Keystone RBAC policy enforcer in enforce call unconditionally merges the raw JSON request body into the policy enforcement dictionary via policy dict.update(json input.copy()), overwriting trusted target data that was previously set from database lookups. Because flask.request.get json is called with force=True, this works regardless of Content-Type or HTTP method. Any authenticated user can inject arbitrary policy target attributes (e.g., user id, project id) into the request body to bypass RBAC checks and perform unauthorized operations on resources belonging to other users or projects. This was introduced in commit 5ea59f52 (Rocky/14.0.0).