The air shower simulation code CORSIKA has served as a key part of the simulation chain for
numerous astroparticle physics experiments over the past decades. Due to retirement of the original
developers and the increasingly difficult maintenance of the monolithic Fortran code of CORSIKA,
a new air shower simulation framework has been developed over the course of the last years in C++,
called CORSIKA 8. Besides the hadronic and muonic component, the electromagnetic component
is one of the key constituents of an air shower. The cascade producing the electromagnetic
component of an air shower is driven by bremsstrahlung and photoproduction of electron-positron
pairs. At ultrahigh energies or in media with high densities, the bremsstrahlung and pair production
processes are suppressed by the Landau-Pomeranchuk-Migdal (LPM) effect, which leads to more
elongated showers compared to showers without the LPM suppression. Furthermore, photons
at higher energies can produce muon pairs or interact hadronically with nucleons in the target
medium, producing a muon component in electromagnetic air showers. In this contribution, we
compare electromagnetic showers simulated with the latest Fortran version of CORSIKA and
CORSIKA 8, which uses the library PROPOSAL for the electromagnetic component. While
earlier validations of CORSIKA 8 electromagnetic showers focused on showers of lower energy,
the recent implementation of the LPM effect, photo pair production of muons, and of photohadronic
interactions allows now to make a physics-complete comparison also at high energies.