Here is a start, under the collections tab there are multiple anthologies containing multiple works. https://imslp.org/wiki/Category:Cabezón,_Antonio_de

It is rather strange that there don’t seem to be any mainstream publishers carrying his works. (At least not that I’m finding states side). Alfred Music has what appears to be the first in a series but it’s out of stock.

I also found a reference to Barenreiter carrying at least four volumes of ‘selected works’ but it also appears to be out of stock (at least at this third party site): https://www.prestomusic.com/sheet-music/products/7816311--cabezon-antonio-de-selected-works-for-keyboard-volumes-i-iv

If you can find your way to a good academic library, you might find de Cabezón's Obras de música in an edition published by the Instituto Español de Musicología, Barcelona 1966, ed. Felipe Pedrell and Higinio Anglés. The last time I looked it up, the call numbers were M2 M4845. It's a multi-volume edition, likely intended for libraries rather than for practising musicians.

I thought that Barenreiter would have it and I was right.
They do... for around $160.

Ha! Not even if it were but a single volume it wouldn't be surprising these days!

I was of course wrong about the Kalmus, which is a reprint of Angles/Pedrell that, based on the IMSLP icon, I mistook for a vertical format. At about $10 x 6 vols. it's still a deal.