Q:

What sin(s) did Prophet Isa commit that required forgiveness from Allah? 

I understand that Islam does not acknowledge inherited sin, that we are all born sinless. 
Prophet Adam sinned by disobeying Allah and had to be forgiven. 
Prophets Noah, Abraham and Moses are all acknowledged to have sinned, but were forgiven. 
Even the Prophet Muhammad sinned and had to ask Allah for forgiveness:

So know, [O Muhammad], that there is no deity except Allah and ask forgiveness for your sin and for the believing men and believing women.  And Allah knows of your movement and your resting place. ( Surat Muhammad 47:19)

According to the Qur’an, what sin(s) did Isa commit that required forgiveness? 

A:

The theological Islamic position is that prophets can not commit sins, (see here).  What is attributed to e.g.  Noah, Abraham, Moses عليه السلام etc.  are not actual sins - rather excusable or lawful matters over which they repent out of their extreme piety and because of holding themselves more strictly accountable in view of their status and relationship with Allah. 
47:19 does not mention a sin of the Prophet Muhammad ﷺ and if you look at its exegesis there are various explanations on whether it is addressed to the Prophet or an ummati, and in which of their possible meanings the words غفر (forgive) and ذنب (sin) are used. 
Regarding the incidents over which the prophets repented: One is not necessarily attributed to all prophets, and Jesus عليه السلام is among those prophets regarding whom nothing of the sort is mentioned in the Quran.  Although from hadith it may be construed that he is concerned over people committing shirk using him, see Views on the sinlessness of Jesus/Isa

