in question vs dubious

in question and dubious both are adjectives.

Word	Noun	Adjective	Verb	Adverb
in question	No	Yes	No	No
dubious	No	Yes	No	No

As adjectives, in question and dubious are synonyms defined as:

Other synonyms of in question include doubtful, dubitable.

in question (adjective)	dubious (adjective)
open to doubt or suspicion	open to doubt or suspicion
	fraught with uncertainty or doubt
	not convinced