The 37-year-old was set upon by a group of men with weapons in Belville Street, Greenock, Inverclyde, at around 11.45pm on Friday.
She was taken by ambulance to Glasgow's Queen Elizabeth University Hospital, where she is being treated for her injuries.
Police are treating the attack as attempted murder.
A 43-year-old man seriously assaulted in the same incident is being treated for a head injury at the hospital.
Two men, aged 31 and 36, have been arrested.
Detective Sergeant Ross MacDonald said: "This was an extremely violent attack on this man and woman and I am appealing to anyone who was in the Belville Street area around the time of the incident last night, who may have witnessed this attack take place, or who was driving by and may have dash-cam footage, to come forward to police.
"I would like to speak to the driver of a grey Mini who was in the street at the time, as she may have information that is vital to this investigation.
"Officers are currently carrying out inquiries in the local area, and uniformed officers are also providing public reassurance, and I would ask anyone with concerns to speak to officers."