  The first all-sky maps of the diffuse emission of high ionization lines
observed in X-rays by SRG/eROSITA, provide an excellent probe for the study of
the warm-hot phase (T~10^6 K) of the circumgalactic medium (CGM) of the Milky
Way (MW). In this work we analyse the O VIII line detected in the first eROSITA
All-Sky Survey data (eRASS1). We fit a sky map made in a narrow energy bin
around this line, with physical emission models embedded in a 3D geometry to
constrain the density distribution of the warm-hot gas around our Galaxy, with
a focus on mid and high (absolute) Galactic latitudes. By masking out the
eROSITA bubbles and other bright extended foreground sources, we find that an
oblate geometry of the warm-hot gas (T~0.15-0.17 keV), flattened around the
Galactic disk with scale height z_h~1-3 kpc, best describes the eRASS1 O VIII
map, with most of the observed emission resulting to be produced within a few
kpc from the Sun. The additional presence of a large scale warm-hot spherical
halo, while providing a minor contribute to the X-ray emission, accounts for
the high O VII absorption column densities detected with XMM-Newton, as well as
most of the baryon budget of the CGM of the MW. The eROSITA data carry the
largest amount of information and detail of O VIII CGM intensities to date,
allowing for a significant reduction of the statistical uncertainties of the
inferred physical parameters.
