OpenImageIO before 3.0.20.0, 3.1.x before 3.1.15.0, and 3.2.x before 3.2.0.3-beta1 contains an integer overflow in cineon::Codec::Read that undersizes the scanline buffer, causing a heap out-of-bounds read. Attackers can supply a crafted Cineon file with a huge declared width that wraps the size calculation to zero, so UnPackPacked reads past a 4-byte buffer and crashes the application.