Yes, all the hadiths related to the virtues of 15th of Shaban are weak, but all the scholars of hadith agree that it is lawful to practice weak hadiths if it is related to fazail (virtues). However, it is not lawful to practice weak hadiths if it is related to ahkam (commandments). No special worship is narrated in this night. However, if someone wants to pray he may do so in his house individually. People should not give it celebration look in the pathways or in the mosques during this night; it is the practice of Ahl Batil (deviants).
Allah knows Best!
Darul Uloom Deoband