Maintenance and security release of the Drupal 8 series.
This release fixes security vulnerabilities. Sites are urged to upgrade immediately after reading the notes below and the security announcements:
No other fixes are included.
No changes have been made to the .htaccess, web.config, robots.txt or default settings.php files in this release, so upgrading custom versions of those files is not necessary.
See the list of the known issues for the 8.1.x branch. There are no known regressions in this release.