The graphite2::TtfUtil::CmapSubtable12Lookup function in Graphite 2 before 1.3.6, as used in Mozilla Firefox before 45.0 and Firefox ESR 38.x before 38.7, allows remote attackers to cause a denial of service (buffer over-read) or possibly have unspecified other impact via a crafted Graphite smart font, a different vulnerability than CVE-2016-2801.