- Bug #5252: Null values are not properly handled by `RangeValidator` (githubjeka, qiangxue)
- Bug #5260: `yii\i18n\Formatter::decimalSeparator` and `yii\i18n\Formatter::thousandSeparator` where not configurable when intl is not installed (execut, cebe)
- Bug #5314: Fixed typo in the implementation of `yii\web\Session::getHasSessionId()` (qiangxue)
- Bug: Date and time formatting now assumes UTC as the timezone for input dates unless a timezone is explicitly given (cebe)