An integer underflow vulnerability exists in pixel-a.asm, the x86 assembly code for planeClipAndMax() in MulticoreWare x265 through 2.4, as used by the x265_encoder_encode dependency in libbpg and other products. A small picture can cause an integer underflow, which leads to a Denial of Service in the process of encoding.
https://bitbucket.org/multicoreware/x265/issues/345/integer-underflow-in-x265-source-common