unassailable vs unattackable

unassailable and unattackable both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unassailable	No	Yes	No	No
unattackable	No	Yes	No	No

As adjectives, unassailable and unattackable are synonyms defined as:

unassailable and unattackable: immune to attack; incapable of being tampered with

Other synonyms of unassailable include impregnable, inviolable, secure, strong.

unassailable (adjective)	unattackable (adjective)
without flaws or loopholes	immune to attack; incapable of being tampered with
impossible to assail
immune to attack; incapable of being tampered with