readfilemap.c in expat before 2.1.0 allows context-dependent attackers to cause a denial of service (file descriptor consumption) via a large number of crafted XML files.
https://support.apple.com/HT205637
http://www.securitytracker.com/id/1034344
http://www.securityfocus.com/bid/52379
http://trac.wxwidgets.org/ticket/11432
http://trac.wxwidgets.org/ticket/11194
http://sourceforge.net/tracker/?func=detail&aid=2895533&group_id=10127&atid=110127
http://sourceforge.net/projects/expat/files/expat/2.1.0/
http://lists.apple.com/archives/security-announce/2015/Dec/msg00005.html
http://expat.cvs.sourceforge.net/viewvc/expat/expat/xmlwf/readfilemap.c?r1=1.14&r2=1.15