If you are talking about the top end (the end that slides up the metal tube into the handle), yes you can repair this easily.
Ours was forever coming off, and refitting didn't seem to be an effective permanent solution.
This is what I did about a year ago, and it hasn't come off since.
Take the end apart (you will need some small screwdrivers to flex the outer part enough to allow the yellow (in my case) inner to slide out. Watch out for the springs on the suction reduction valve, these will probably pop out and go anywhere!
Remove the old broken hose end, trim the hose back so that the end is as 'square' as possible (you will need wire cutters for the wire, and a sharp craft knife for the plastic). Then CLEAN the end of the hose as much as possible, inside and out, and the grooves in the end onto which the hose 'screws'.
Before re-assembly, put the suction reducer valve back in place, and fiddle the 2 springs into their slots (easier said than done but persevere and it gets easier with practice).
Now here's the bit that really cures the problem, mix up some 2-part adhesive such as Araldite Rapid, coat the 'screw' part thoroughly, and refit the hose to the screw, turning it until the wire end meets its natural stop in the screw. Leave this to go off (depends on what glue you use), then you can re-insert the hose end into its housing until it 'snaps' back into place.
Now for the tricky part, hang the hose up somwhere, mix some more adhesive, and use a cocktail stick or similar to feed as much glue as possible into the gap between the housing and the hose, it should 'run' intoi the gap as you put more in. Not all glues 'run' as much as Araldite Rapid so I would recommend this. When you've got a good fill of glue, leave the whole thing hanging until it has gone off.
Hopefully, this will be as effective as the repair I made to our Dyson - Good Luck
dave b, December 2004