Measurements of vertical bar Vub vertical bar and vertical bar Vcb vertical bar from CLEO

I report results from the CLEO collaboration on semileptonic B decays, highlighting measurements of the Cabibbo-Kobayashi-Maskawa matrix elements vertical bar Vub vertical bar and vertical bar Vcb vertical bar. I describe the techniques used to obtain the recent improvements in precision for these measurements, notably the use of the b → sγ photon spectrum to constrain non-perturbative hadronic effects in semileptonic B decays