Curable composition, cured film, color filter, protective film, display device and solid-state imaging element

Provided is a curable composition including: (A) a compound containing at least two ethylenic unsaturated double-bonded groups, and at least one second-class hydroxyl group; (B) a resin containing an acidic group in the side-chain; (C) at least one type of initiator selected from a group comprising of photopolymerization initiators and thermal polymerization initiators; (D) a photoacid generator; and (E) an acid crosslinking compound. Also provided is a curable composition including: (A) a compound containing at least two ethylenic unsaturated double-bonded groups, and at least one second-class hydroxyl group; (B) a resin containing an acidic group in the side-chain; (C) at least one type of initiator selected from a group comprising of photopolymerization initiators and thermal polymerization initiators; (D') a thermal acid generator; and (E) an acid crosslinking compound. Further provided are a cured film, a color filter, a protective film, a display device, and a solid imaging element that use the curable compositions.