A measurement of the K^+→π^+νν decay by the NA62 experiment at the CERN SPS is presented, using data collected in 2021 and 2022. This dataset was recorded, after modifications to the beamline and detectors, at a higher instantaneous beam intensity with respect to the 2016–2018 data taking. Combining NA62 data collected in 2016–2022, a measurement of ℬ(K^+→π^+νν)=(13.0_-3.0^+3.3)×10^-11 is reported. With 51 signal candidates observed and an expected background of 18_-2^+3 events, ℬ(K^+→π^+νν) becomes the smallest branching ratio measured with a signal significance above 5σ.
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