libde265 is an open source implementation of the h.265 video codec. Prior to version 1.1.0, a crafted H.265 bitstream with large SPS dimensions and 16-bit bit depth causes a signed integer overflow in de265_image_get_buffer() (libde265/image.cc:128). The overflow wraps the plane allocation size to a small value (~1 KB), but the subsequent fill_image() call computes the real size using size_t, writing ~4 GB into the undersized heap buffer. Version 1.1.0 patches the issue.