A 25-year-old man was found injured at Waterloo Millennium Green at 7.40pm on October 8.
He treated at the scene by paramedics before being taken to hospital.
His injuries were initially assessed to be life-changing but in an update, police confirmed his condition has improved and is no longer classed to be this severe.
There have been no arrests in relation to this incident.
A Metropolitan Police spokesperson said after the incident: “Police were called at 19:40hrs on Wednesday, 8 October to reports of a stabbing on Waterloo Millennium Green, SE1.
“Officers attended and a man, aged 25, was being treated by the London Ambulance Service. He was taken to hospital and his condition is believed to be life-changing.
“A crime scene was put in place and enquiries are ongoing.
“There have b