cairo through 1.15.14 has an out-of-bounds stack-memory write during processing of a crafted document by WebKitGTK+ because of the interaction between cairo-rectangular-scan-converter.c (the generate and render_rows functions) and cairo-image-compositor.c (the _cairo_image_spans_and_zero function). https://nvd.nist.gov/vuln/detail/CVE-2018-18064
