We show that if 𝐺 is an admissible group acting geometrically on a
CAT
(
0
)
\operatorname{CAT}(0)
space 𝑋, then 𝐺 is a hierarchically hyperbolic space and its 𝜅-Morse boundary
(
∂
κ
G
,
ν
)
(\partial_{\kappa}G,\nu)
is a model for the Poisson boundary of
(
G
,
μ
)
(G,\mu)
, where 𝜈 is the hitting measure associated to the random walk driven by 𝜇.