The day after WordPress pushed out a critical 5.5.2 security update, patching a remote code execution bug and nine additional flaws, it was forced push out a second update and then a third 5.3 update. The issue was corrected quickly on Oct. 30, but not before WordPress site operators reported new WordPress installs failing and others grousing over broken administration login pages. WordPress said a final version of the 5.4.2-alpha update is now available. The auto-update feature started sending 455 million websites a WordPress update that caused new installs to fail. The error only affected fresh installations without an existing wp-config.php file in place.
Source: https://threatpost.com/wordpress-flawed-security-updates/160849/