Short sales are sold "AS IS". Typically the lender who had got the appraisal/BPO done on the home has accounted for the repairs if noted by that appraiser/Realtor.
You can discuss with your Realtor and have him/her speak to the listing agent.
If you want to renogiate it may take either longer time to get the new priced approved, depending on how behind seller is and where the foreclosure is on the home if they are behind the short sale lender may negotiate or not.
You can try. Have your Realtor do an Addendum or a Request For Repairs (if you want the lender/seller to do the repairs). Worse case, the lender/seller says 'no'. Then you can either move forward as is or cancel contract - assuming you have inspection contingencies in effect.
Talk to your Realtor.