  We explore the possibility of lepton number violation (LNV) manifesting in
the rare kaon decay $K\to\pi\nu\nu$, and its consequences for radiative
neutrino mass generation and the washout of Lepton asymmetry in high-scale
leptogenesis scenarios. We perform the analysis in a model-independent
framework, the Standard Model effective field theory (SMEFT), and discuss the
possible LNV nature of the rare kaon decay in the context of the currently
operating NA62 experiment at CERN. We find that, in case of a LNV interaction,
its detection would put high-scale leptogenesis under tension and would hint to
small radiatively generated neutrino masses.
