We just released Mastodon 4.2.13 and 4.1.20. They contain a few bug fixes, a security fix (high severity, only impacting Ruby <= 3.2) and a critical security in a dependency is you use SAML authentication (CVE-2024-45409).
Release notes and upgrade instructions are available on our GitHub Releases page: https://github.com/mastodon/mastodon/releases/