  In view of the recent results from the MiniBooNE experiment we revisit the
global neutrino oscillation fit to short-baseline neutrino data by adding one
or two sterile neutrinos with eV-scale masses to the three Standard Model
neutrinos, and for the first time we consider also the global fit with three
sterile neutrinos. Four-neutrino oscillations of the (3+1) type have been only
marginally allowed before the recent MiniBooNE results, and become even more
disfavored with the new data (at the level of $4\sigma$). In the framework of
so-called (3+2) five-neutrino mass schemes we find severe tension between
appearance and disappearance experiments at the level of more than $3\sigma$,
and hence no satistfactory fit to the global data is possible in (3+2) schemes.
This tension remains also when a third sterile neutrino is added, and the
quality of the global fit does not improve significantly in a (3+3) scheme. It
should be noted, however, that in models with more than one sterile neutrino
the MiniBooNE results are in perfect agreement with the LSND appearance
evidence, thanks to the possibility of CP violation available in such
oscillation schemes. Furthermore, if disappearance data are not taken into
account (3+2) oscillations provide an excellent fit to the full MiniBooNE
spectrum including the event excess at low energies.
