Product
An authorization bypass vulnerability in the `@better-auth/stripe` library allows authenticated users to perform subscription actions (cancel, change plan, restore, open billing portal) against other organizations they are a member of, but not authorized to manage. This occurs due to inconsistent handling of organization IDs between the middleware, which approves the ID from the request query string, and the route handler, which acts on the active organization ID from the session or request body. This flaw enables users to access sensitive billing details and manipulate subscriptions for unintended organizations.