NET
19 Although these false teachers promise such people freedom, they themselves are enslaved to immorality. For whatever a person succumbs to, to that he is enslaved.
Darby
19 promising them liberty, while they themselves are slaves of corruption; for by whom a man is subdued, by him is he also brought into slavery.
KJV
19 While they promise them liberty, they themselves are the servants of corruption: for of whom a man is overcome, of the same is he brought in bondage.