Latest PHP Security Fix announced
It is a Bug Fix. Previous release (7.4.18) was a SECURITY RELEASE.
Are YOU checking which version and release of PHP is being used by your Joomla! website?
We strongly recommend that you periodically check which release is being provided by your hosting provider for the PHP version used by your website.
Always request that they provide the latest available security release.
Use PHP 7.4 if you are using the latest available release of Joomla! CMS (recommended).
We tell you how to check which PHP version/release is being used by your Joomla! website in our JOOMLERS.UK User Guide.
How to check which PHP version is being used
You can quickly check the version of PHP after signing into your website's control panel.
Select System > System Information from the menu at the top of the control panel screen.
If the version of PHP used by your website is earlier than PHP 7.4, use the PHP Selector in your Hosting Control Panel to upgrade PHP.
Or contact your hosting provider and request an upgrade.
Reason: your website will perform better and it will be more secure.
Always use the latest available release of PHP version with the latest available release of Joomla! CMS.