Action Pack is a framework for handling and responding to web requests. Under certain circumstances response bodies will not be closed. In the event a response is *not* notified of a `close`, `ActionDispatch::Executor` will not know to reset thread local state for the next request. This can lead to data being leaked to subsequent requests.This has been fixed in Rails 7.0.2.1, 6.1.4.5, 6.0.4.5, and 5.2.6.1. Upgrading is highly recommended, but to work around this problem a middleware described in GHSA-wh98-p28r-vrc9 can be used.

A open redirect vulnerability exists in Action Pack >= 6.0.0 that could allow an attacker to craft a "X-Forwarded-Host" headers in combination with certain "allowed host" formats can cause the Host Authorization middleware in Action Pack to redirect users to a malicious website.

A cross-site scripting vulnerability flaw was found in the auto_link function in Rails before version 3.0.6.

A possible open redirect vulnerability in the Host Authorization middleware in Action Pack >= 6.0.0 that could allow attackers to redirect users to a malicious website.

The actionpack ruby gem (a framework for handling and responding to web requests in Rails) before 6.0.3.7, 6.1.3.2 suffers from a possible denial of service vulnerability in the Mime type parser of Action Dispatch. Carefully crafted Accept headers can cause the mime type parser in Action Dispatch to do catastrophic backtracking in the regular expression engine.

The actionpack ruby gem before 6.1.3.2 suffers from a possible open redirect vulnerability. Specially crafted Host headers in combination with certain "allowed host" formats can cause the Host Authorization middleware in Action Pack to redirect users to a malicious website. This is similar to CVE-2021-22881. Strings in config.hosts that do not have a leading dot are converted to regular expressions without proper escaping. This causes, for example, `config.hosts << "sub.example.com"` to permit a request with a Host header value of `sub-example.com`.

The actionpack ruby gem before 6.1.3.2, 6.0.3.7, 5.2.4.6, 5.2.6 suffers from a possible denial of service vulnerability in the Token Authentication logic in Action Controller due to a too permissive regular expression. Impacted code uses `authenticate_or_request_with_http_token` or `authenticate_with_http_token` for request authentication.

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.

The activerecord-session_store (aka Active Record Session Store) component through 1.1.3 for Ruby on Rails does not use a constant-time approach when delivering information about whether a guessed session ID is valid. Consequently, remote attackers can leverage timing discrepancies to achieve a correct guess in a relatively short amount of time. This is a related issue to CVE-2019-16782.

The Host Authorization middleware in Action Pack before 6.1.2.1, 6.0.3.5 suffers from an open redirect vulnerability. Specially crafted `Host` headers in combination with certain "allowed host" formats can cause the Host Authorization middleware in Action Pack to redirect users to a malicious website. Impacted applications will have allowed hosts with a leading dot. When an allowed host contains a leading dot, a specially crafted `Host` header can be used to redirect to a malicious website.