A 50-year-old man from Banbury has been arrested on suspicion of causing grievous bodily harm with intent after a fight involving a knife at a house in Harlech Close on Saturday.
Two other men have been arrested on suspicion of attempted burglary following the incident.
The altercation took place early in the morning between 12.30am and 12.45 when two men attempted to enter the property. When they were unable to do so they climbed on to a roof and tried to gain access via a window.
As they did so one of the men, aged in his twenties, sustained knife wounds to his chest, neck and arm. He was taken to John Radcliffe Hospital in Oxford where he remains.
The other man, also aged in his twenties, sustained a nose injury and a cut finger. He was treated at Horton General Hospital in Banbury and has since been discharged.
The 50 year-old man was bailed until August 1, while two men, aged 22 and 28, also from Banbury, have been arrested on suspicion of attempted burglary and bailed until August 25 and August 21.
Investigating officer detective constable Mark Personius, from Banbury Force CID, said: “I would like to speak to anyone who saw the altercation near the window of the property in Harlech Close.
“I would also like to speak to anyone who saw anyone acting suspiciously in the area at the time of the incident or anyone who has any information which could assist the investigation.”
Anyone with any information should call the 24-hour Thames Valley Police enquiry centre on 101.
If you do not want to speak directly to the police you can contact the independent charity Crimestoppers anonymously on 0800 555 111. No personal details are taken, information is not traced or recorded and you will not go to court.