An emergency update of WordPress 5.5.3 has been released by the WordPress core team, just one day after version 5.5.2 was released. This emergency update was made to fix a problem implemented in WordPress 5.5.2, making it difficult to run WordPress without a database link installed on a brand new website. A second problem caused a number of pages to be erroneously upgraded to version 5.5.3-alpha while planning for this emergency upgrade.
According to the release notes, the WordPress auto-update framework upgraded some pages from version 5.5.2 to 5.5.3-alpha between about 15:30 and 16:00 UTC on October 30th. This happened because, in an effort to discourage new users from using this update, the WordPress Core team blocked the 5.5.2 release download. By deleting the 5.5.2 download, the wordpress.org API returned the 5.5.3-alpha-49449 alpha version as the version that WordPress can migrate to.
An overview of the release 5.5.3-alpha-49449 showed no distinction between the release 5.5.2 of WordPress and 5.5.3-alpha-49449 of WordPress, since much of the key features is the same. Owing to the mistake, no recorded site functionality was disabled. However, along with the Akismet plugin, a number of additional Twenty- themes were built with that autoupdate.
To fix both concerns, download 5.5.2 was originally re-enabled by the Core team to discourage sites from upgrading to the alpha version, followed by the WordPress 5.5.3 emergency release to resolve the issue that stopped new install.
What Should I Have Done?
If your WordPress 5.5.3-alpha site has been upgraded, you can have additional themes built on your site. You may have Akismet mounted as well. When installed as part of the pre-release kit, these themes and plugins were not allowed. Check the themes and installation of plugins. There will be no other plugins installed or deleted.
Upgrade the pages to WordPress 5.5.3 normally, just as you will on every other update to WordPress. If you want your site to auto-update, you will already have version 5.5.3 enabled.
If you haven’t upgraded to 5.5.2 for WordPress yet, upgrading to 5.5.3 is exactly the same version with a slight patch. It is secure to upgrade your site.