- Bug #17828: Fix `yii\web\UploadedFile::saveAs()` failing when error value in `$_FILES` entry is a string (haveyaseen)
- Bug #17829:`yii\helpers\ArrayHelper::filter` now correctly filters data when passing a filter with more than 2 levels (rhertogh)
- Enh #7622: Allow `yii\data\ArrayDataProvider` to control the sort flags for `sortModels` through `yii\data\Sort::sortFlags` property (askobara)
- Enh #16721: Use `Instance::ensure()` to initialize `UrlManager::$cache` (rob006)
- Bug #17863:`\yii\helpers\BaseInflector::slug()` doesn't work with an empty string as a replacement argument (haruatari)
- Bug #17881:`yii\db\Query::queryScalar()` wasn’t reverting the `select`, `orderBy`, `limit`, and `offset` params if an exception occurred (brandonkelly)
- Bug #17875: Use `move_uploaded_file()` function instead of `copy()` and `unlink()` for saving uploaded files in case of POST request (sup-ham)