Is the hadith stating that the best fasting is fasting in Shaaban to honour Ramadan authentically attributed to the Prophet?

Summary

The hadith is narrated from Anas bin Malik in several hadith collections, but its chain centres on Ṣadaqah bin Mūsā, who is regarded as weak in memorisation. Although two reliable narrators transmit from him, the report remains a solitary one and no other chain supports it. Even so, its weakness does not negate the recommendation to fast in Shaaban, as many authentic hadiths report that the Prophet fasted in that month.

Written in our own words from the original fatwa — check the source before acting on it.