Galifianakis, 43, is known for his role of Alan Garner in the comedy movie franchise that also stars Bradley Cooper, Ed Helms and Justin Bartha.
''I have heard the rumours about her (Cole) making a cameo and there seems to be something to them. But I don't know if anything's signed yet," FHM magazine quoted Galifianakis as saying.
The movie franchise began with "Hangover" in 2009 followed by "The Hangover Part II" in 2011. All three movies have been directed by Todd Phillips.