We know security updates can be distracting but we take security very seriously and do not want to delay getting you the latest enhancements. As we continue to audit security hardening, we will do these focused update releases.
This release addresses two possible XSS scenarios.
An issue has been identified with PHP 7.1 when using the Zend OPcache extension that may cause features on your site, such as member posting, not to work correctly. If you are experiencing problems posting, please disable the Zend OPcache PHP extension. The underlying issue is related to a third party library used by the Community Suite which has been updated in our upcoming 4.2 release, at which point the OPcache extension may be re-enabled.