With the launch of WordPress 5.2 the minimum supported PHP version has been raised to PHP 5.6.
WordPress hosted on servers with less than PHP 5.6 will no longer be able to update and will see an error which reads
Your server is running PHP version 5.5.38 but WordPress 5.2 requires at least 5.6.20.
Since 2017 the WordPress community has been working towards raising the supported PHP version. This began with creating the servehappy project.
While PHP 5.6 is considered end-of-life – because it no longer receives maintenance or security fixes – this is still a big step forward for WordPress.
Eventually WordPress will only support the PHP versions that are receiving maintenance and security updates. However, this needs to be a slow and incremental process to as one of the core tenets of WordPress is backwards compatibility.
The next version bump will be the most significant – affecting the most WordPress installations with 31.3% currently using PHP 5.6.
This is expected to be in December 2019 and will go to PHP 7.0.
The benefits of running the latest version of PHP goes beyond security – it also allows developers to use new features and improved load speeds.