There is currently a significant tension between the prediction from the unitarity of the first row of the CKM matrix, $|V_{ud}|^{2} +|V_{us}|^{2} + |V_{ub}|^{2} =1$, and measurements.
This is known as the Cabibbo angle anomaly, with the tension corresponding to around three standard deviations.
Precision measurements linked to kaon physics can provide insights into $V_{ud}$ and $V_{us}$.
In particular, studies of $K\rightarrow\pi\ell\nu$ decays can provide a measurement of $V_{us}$ and the ratio between the rates of $K^{\pm}\rightarrow\mu^{\pm}\nu$ and $\pi^{\pm}\rightarrow\mu^{\pm}\nu$ decays can provide a measurement of the ratio $|V_{us}|/|V_{ud}|$.
Future measurements of these CKM parameters using current and future experiments can play a crucial role in resolving the current tension between observations and the prediction from unitarity.
In these proceedings the current state-of-the-art in CKM metrology from kaon physics is presented, and future prospects are summarised.