WordPress 5.5.3 Maintenance Release

This maintenance release fixes an issue introduced in WordPress 5.5.2 which makes it impossible to install WordPress on a brand new website that does not have a database connection configured.

WordPress 5.5.2 Security and Maintenance Release

Security Updates

• Props to Alex Concha of the WordPress Security Team for their work in hardening deserialization requests.
• Props to David Binovec on a fix to disable spam embeds from disabled sites on a multisite network.
• Thanks to Marc Montas from Sucuri for reporting an issue that could lead to XSS from global variables.
• Thanks to Justin Tran who reported an issue surrounding privilege escalation in XML-RPC. He also found and disclosed an issue around privilege escalation around post commenting via XML-RPC.
• Props to Omar Ganiev who reported a method where a DoS attack could lead to RCE.
• Thanks to Karim El Ouerghemmi from RIPS who disclosed a method to store XSS in post slugs.
• Thanks to Slavco for reporting, and confirmation from Karim El Ouerghemmi, a method to bypass protected meta that could lead to arbitrary file deletion.
• Thanks to Erwan LR from WPScan who responsibly disclosed a method that could lead to CSRF.
• And a special thanks to @zieladam who was integral in many of the releases and patches during this release.