There is a vulnerability in actionpack_page-caching gem < v1.2.1 that allows an attacker to write arbitrary files to a web server, potentially resulting in remote code execution if the attacker can write unescaped ERB to a view.
actionpack_page-caching
CVE-2021-22885
A possible information disclosure / unintended method execution vulnerability in Action Pack >= 2.0.0 when using the `redirect_to` or `polymorphic_url`helper with untrusted user input.