The issue allows remote attackers to cause a denial of service, resulting in an invalid read of two bytes and application crash. This is due to mishandling of GPOS and GSUB tables, related to files such as `hb-ot-layout-gpos-table.hh`, `hb-ot-layout-gsub-table.hh`, and `hb-ot-layout-gsubgpos-private.hh`.