Carbacanthographis spongiosa is a species of corticolous (bark-dwelling) lichen in the family Graphidaceae.

Found in Brazil, it was formally described as a new species in 2022 by Shirley Cunha Feuerstein and Robert Lücking.

The type specimen was collected from Atlantic Forest on a private property in Santa Luzia do Itanhy (Sergipe).

The specific epithet spongiosa refers to the spongy texture of the thallus surface.

It has hyaline ascospores that measure 23–25 by 6–7 μm; these spores have between 6 and 8 transverse septa.