oven frame

I have a Wren kitchen (10 years old) and it was fitted with a double oven - it was fitted in a 600mm void that had side panels inserted on each side and and an oven 'bracket' that it rested on. I've taken it out and fitted the new NEFF without issue, however as the NEFF is a single there is not...

I need to replace my oven and have pulled it out to look at the 'frame' that holds it. The screws that held the oven in had come loose and on inspection I can see the chipboard has splintered around where the holes are (see below). Whats the best thing to fills the holes. The chipboard...