FFmpeg through 9.0.2 contains an out-of-bounds read vulnerability in the prores_ks encoder's get_alpha_data() that…

FFmpeg through 9.0.2 contains an out-of-bounds read vulnerability in the prores_ks encoder's get_alpha_data() that reads before the blocks buffer for interlaced frames with odd heights. Attackers can supply video with alpha and odd height encoded to interlaced ProRes 4444, causing out-of-bounds memory to be encoded into the output alpha plane.