  The hyperon vector form factors at zero momentum transfer, $f_1(0)$, play an
important role in a precise determination of the Cabibbo-Kobayashi-Maskawa
matrix element $V_{us}$. Recent studies based on lattice chromodynamics (LQCD)
simulations and covariant baryon chiral perturbation theory yield contradicting
results. In this work, we study chiral extrapolation of and finite-volume
corrections to the latest $n_f=2+1$ LQCD simulations. Our results show that
finite-volume corrections are relatively small and can be safely ignored at the
present LQCD setup of $m_\pi L=4.6$ but chiral extrapolation needs to be
performed more carefully. Nevertheless, the discrepancy remains and further
studies are needed to fully understand it.
