Is it permissible to hold a celebration for circumcision, and is this considered Sunnah or an innovation?

It is permissible to hold a banquet (walima) for the circumcision of a newborn, to express joy and happiness, and to thank Allah Almighty for His bounty, as mentioned by Ibn Qudamah in "Al-Mughni" and by the scholars of the Permanent Committee. This is on the condition that no special virtue is attributed to it that has not been mentioned in the Sharia (definition), but rather it should be like any other invitation intended to thank Allah for His blessing and to feed one's brethren.