Studies of top quark spin and polarization in CMS

We describe the latest results obtained by the CMS Collaboration on top quark spin and polarization properties. The top quark spin asymmetry is measured both targeting single-top quark production in the $t$-channel and single-top quark production in association with a Z boson. Additionally, all the independent coefficients of the spin-dependent part of the top quark-antiquark production density matrix are measured and the results are extrapolated to the High-Luminosity LHC scenario.