  The combination of precise determinations of $V_{us}$ and $V_{ud}$ hints
towards a violation of the CKM first row unitarity at about $3\sigma$ level.
Conversely, the recent measurement of the $W$-boson mass by the CDF
Collaboration exhibits significant tension with the SM prediction, intensifying
the conflict that may arise in models addressing the unitarity violation. We
demonstrate that one vector-like $SU(2)_L$ doublet with mass of a few TeV
mixing with light quarks and the top quark can simultaneously account for the
two anomalies, without conflicting with flavour-changing phenomena and
electroweak observables. Moreover, another tension in the value of the Cabibbo
angle is reported also at $3\sigma$ level, between two determinations of
$V_{us}$ obtained from semi-leptonic $K\ell3$ and leptonic $K\mu 2$ kaon
decays. We show that the vector-like doublet can be at the origin of this
discrepancy and the substantial positive shift in the $W$-boson mass. This
unique feature of the vector-like quark doublet may render it a crucial puzzle
piece in new physics scenarios addressing the CKM unitarity problem. The model
can be potentially probed in future colliders.
