The double Higgs production is the only direct probe of the Higgs self-coupling interaction, and could prove to be a valuable source of information about the scalar potential. Due to destructive interference, the cross-section of this process is heavily suppressed and remains a challenging measurement. This document presents the different non-resonant analyses, public as of July 2022, performed by the CMS collaboration using the 138~fb$^{-1}$ data of Run-2 in the various decay channels, as well as their combination. Results are interpreted in terms of cross-sections and couplings, notably the trilinear Higgs interaction.