Stack consumption vulnerability in CoreAnimation in Apple Mac OS X before 10.8.4 allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via a crafted text glyph in a URL encountered by Safari.
Apple Security Advisory 2013-06-04-1 - OS X Mountain Lion version 10.8.4 and Security Update 2013-002 is now available and addresses over 30 security issues.