  We report on the masses ($M_\mathrm{WD}$), effective temperatures
($T_\mathrm{eff}$) and secular mean accretion rates ($\langle \dot{M} \rangle$)
of 43 cataclysmic variable (CV) white dwarfs, 42 of which were obtained from
the combined analysis of their $\mathit{Hubble~Space~Telescope}$ ultraviolet
data with the parallaxes provided by the Early Third Data Release of the
$\mathit{Gaia}$ space mission, and one from the white dwarf gravitational
redshift. Our results double the number of CV white dwarfs with an accurate
mass measurement, bringing the total census to 89 systems. From the study of
the mass distribution, we derive $\langle M_\mathrm{WD} \rangle =
0.81^{+0.16}_{-0.20}\,\mathrm{M_\odot}$, in perfect agreement with previous
results, and find no evidence of any evolution of the mass with orbital period.
Moreover, we identify five systems with $M_\mathrm{WD} < 0.5\mathrm{M_\odot}$,
which are most likely representative of helium-core white dwarfs, showing that
these CVs are present in the overall population. We reveal the presence of an
anti-correlation between the average accretion rates and the white dwarf masses
for the systems below the $2-3\,$h period gap. Since $\langle \dot{M} \rangle$
reflects the rate of system angular momentum loss, this correlation suggests
the presence of an additional mechanism of angular momentum loss that is more
efficient at low white dwarf masses. This is the fundamental concept of the
recently proposed empirical prescription of consequential angular momentum loss
(eCAML) and our results provide observational support for it, although we also
highlight how its current recipe needs to be refined to better reproduce the
observed scatter in $T_\mathrm{eff}$ and $\langle \dot{M} \rangle$, and the
presence of helium-core white dwarfs.
