Rails is a web-application framework. Starting with version 5.2.0, there is a possible sensitive session information leak in Active Storage. By default, Active Storage sends a Set-Cookie header along with the user's session cookie when serving blobs. It also sets Cache-Control to public. Certain proxies may cache the Set-Cookie, leading to an information leak. The vulnerability is fixed in 7.0.8.1 and 6.1.7.7.