  The Kerr-Schild-Kundt (KSK) metrics are known to be one of the universal
metrics in general relativity, which means that they solve the vacuum field
equations of any gravity theory constructed from the curvature tensor and its
higher-order covariant derivatives. There is yet no complete proof that these
metrics are universal in the presence of matter fields such as electromagnetic
and/or scalar fields. In order to get some insight into what happens when we
extend the "universality theorem" to the case in which the electromagnetic
field is present, as a first step, we study the KSK class of metrics in the
context of Modified Horndeski theories with Maxwell's field. We obtain exact
solutions of these theories representing the $pp$-waves and AdS-plane waves in
arbitrary $D$ dimensions.
