WordPress has released version 5.1.1, a security and maintenance release to patch security holes and bugs. This is the 5th overall release of WordPress 5 since it was first launched on December 6, 2018
Security Upgrades and Patches
v5.1.1 is being called a Security & Maintence release which means a majority of this update is in regards to the security of WordPress.
WordPress says there were 2 bugs that affected v5.1 and earlier versions of WordPress 5 which allowed hackers to use the comments for cross-site scripting. Cross-site scripting (XSS) is a type of website vulnerability that enables attackers to inject client-side scripts into web pages viewed by other users. A cross-site scripting vulnerability may be used by attackers to bypass WordPress’s admin login restrictions allowing them to takeover a website. That makes this update critical, especially so for websites with comments turned on.Note: If you cannot update to 5.1.1 WordPress has update the core code of all other versions of WordPress 5 so far. Those can be downloaded from the WordPress.org website.
Improvements in v5.1.1
Upgrade PHP Notice – Web hosts can now install a button for users to directly upgrade their PHP from the WordPress upgrade PHP notice.
Loading.gif– v5.1.1 contained an update which minifies the Loading.gif image just a little bit more for faster loading.
Upgrade Problems Reported with v5.1.1
WordPress user ‘Laughter on Water’ had a problem upgrading from v5.1 to v5.1.1 with WordPress running on Ubuntu. This user said the problem occurred during the install when everything came to a pause.
This is the error they were given:
$ wp core update
Updating to version 5.1.1 (en_US)...
PHP Fatal error: Call to undefined method WP_Error::has_errors() in /home/myname/mysite.com/wp-admin/includes/file.php on line 1504
Fatal error: Call to undefined method WP_Error::has_errors() in /home/myname/mysite.com/wp-admin/includes/file.php on line 1504
This user found a workaround which you can find here in the references below4 and was able to successfully upgrade after implementing this workaround
No other users have reported major problems with upgrades to v5.1.1 from v5.1 or other versions as of yet.
Next Major Release
The next major release of WordPress 5 will be v5.2 and is expected sometime in April of 2019 with a target general release date of April 23, 2019. v5.2 is likely to include another upgrade to the “Gutenberg” block editor, a merger of the Health Check plugin with the Site Health feature included in v5.1, and PHP error protection.
That version is currently at 13% complete. You can track the progress of v5.2 here http://trac.wordpress.org/milestone/5.2