The ultra-rare $K^{+} \rightarrow \pi^{+}\nu\overline{\nu}$
decay benefits from a precisely predicted branching ratio in the SM
$BR(K^{+} \rightarrow \pi^{+}\nu\overline{\nu}) = (8.4\pm 1.0)\times
10^{-11}$, being almost free from theoretical uncertainties, and
most importantly from a very high sensitivity to a variety of
beyond-the-standard-model scenarios, making it one of the best
candidates to reveal indirect effects of new physics in the flavour
sector. The NA62 experiment at the CERN SPS, designed to measure
the branching ratio of $K^{+} \rightarrow \pi^{+}\nu\overline{\nu}$
with a decay-in-flight technique, collected data in 2016-2018. New
results from the analysis of 2018 data, the largest data set so far
collected, will be presented. The result will represent the most
accurate measurement so far achieved of this ultra-rare decay.