is_blog_installed in wp-includes/functions.php in WordPress before 5.5.2 improperly determines whether WordPress is already installed, which might allow an attacker to perform a new installation, leading to remote code execution (as well as a denial of service for the old installation).
github.com/WordPress/wordpress-develop/commit/2ca15d1e5ce70493c5c0c096ca0c76503d6da07c
lists.debian.org/debian-lts-announce/2020/11/msg00004.html
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CHHVNK2WYAM3ZTCXTFSEIT56IKLVJHU3/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VAVVYJKA2I6CRQUINECDPBGWMQDEG244/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VUXVUAKL2HL4QYJEPHBNVQQWRMFMII2Y/
wordpress.org/news/2020/10/wordpress-5-5-2-security-and-maintenance-release/
wpscan.com/vulnerability/10450
www.debian.org/security/2020/dsa-4784