WordPress before 5.5.2 mishandles deserialization requests in wp-includes/Requests/Utility/FilteredIterator.php.
https://www.debian.org/security/2020/dsa-4784
https://wpscan.com/vulnerability/10446
https://wordpress.org/news/2020/10/wordpress-5-5-2-security-and-maintenance-release/
https://lists.debian.org/debian-lts-announce/2020/11/msg00004.html
https://github.com/WordPress/wordpress-develop/commit/add6bedf3a53b647d0ebda2970057912d3cd79d3