A villager was summoned in with the following command.
/summon Villager ~ ~1 ~ {NoGravity:1b,Profession:0,Invulnerable:1}
Several ghast fireballs hit the villager and the villager and it died
MC-106174
Invulnerable tag does not work with ghast fireballs
Resolved
Cannot Reproduce
0
Cannot reproduce in survival mode.
Be aware that in creative mode, you can damage invulnerable entities, thus redirecting a fireball counts as attacking in creative mode.