In this security release, there are 4 security fixes. It is recommended to update your sites immediately whenever there is a security release. Also, all the versions since WordPress 3.7 have been updated.
The next major release will be version 5.9, which is already in the Release Candidate stage. This WordPress 5.8.3 is a short-cycle security release.
You can update to WordPress 5.8.3 by downloading from WordPress.org or visiting your Dashboard → Updates and clicking Update Now.
If you have sites that support automatic background updates, they’ve already started the update process.
Security Updates
WordPress versions between 3.7 and 5.8 will be affected by these four security issues. If you haven’t yet updated to 5.8, all WordPress versions since 3.7 have also been updated.