Is it obligatory to repeat Maghrib prayer if Isha prayer was performed before its due time?

Your 'Isha prayer is invalid because it was performed before its time, as prayer is only valid when performed at its designated time. The Maghrib prayer is valid if performed within its time, and if you have not yet prayed it, then it must be performed before 'Isha. It is not permissible to delay a prayer beyond its time except for an overwhelming excuse. There is no blame on someone who misses a prayer while asleep.