yiisoft Yii2 MockClass.php generate deserialization

A vulnerability, which was classified as critical, was found in yiisoft Yii2 up to 2.0.39. This affects the function Generate of the file phpunit\src\Framework\MockObject\MockClass.php. The manipulation leads to deserialization. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used.