There is a potential DOM based cross-site scripting issue in rails-ujs which leverages the Clipboard API to target HTML elements that are assigned the contenteditable attribute. This has the potential to occur when pasting malicious HTML content from the clipboard that includes a data-method, data-remote or data-disable-with attribute.

The redirect_to method in Rails allows provided values to contain characters which are not legal in an HTTP header value. This results in the potential for downstream services which enforce RFC compliance on HTTP response headers to remove the assigned Location header.

ActiveSupport::EncryptedFile writes contents that will be encrypted to a temporary file. The temporary file's permissions are defaulted to the user's current `umask` settings, meaning that it's possible for other users on the same system to read the contents of the temporary file. Attackers that have access to the file system could possibly read the contents of this temporary file while a user is editing it. All users running an affected release should either upgrade or use one of the workarounds immediately.

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.