  Compact radio AGN are thought to be young radio active galactic nuclei (AGN)
at the early stage of AGN evolution, thus are ideal laboratory to study the
high-energy emission throughout the evolution of radio AGN. In this work, we
report for the first time the detection of the high-energy cutoff ($E_{\rm
cut}$), a direct indicator of thermal coronal radiation, of X-ray emission in
Mrk 348 ($z$ = 0.015), a young radio galaxy classified as compact symmetric
object. With a 100 ks NuSTAR exposure, we find that the high-energy cutoff
($E_{\rm cut}$ ) is firmly detected ($218^{+124}_{-62}$ keV). Fitting with
various Comptonization models indicates the presence of a hot corona with
temperature $kT_{\rm e}$ = 35 -- 40 keV. These strongly support the corona
origin for its hard X-ray emission. The comparison in the $E_{\rm cut}$ --
spectra index $\Gamma$ plot of Mrk 348 with normal large-scale radio galaxies
(mostly FR II) yields no difference between them. This suggests the corona
properties in radio sources may not evolve over time (i.e., from the infant
stage to mature stage), which is to-be-confirmed with future sample studies of
young radio AGN.
