Buffer overflow in the png_read_IDAT_data function in pngrutil.c in libpng before 1.5.21 and 1.6.x before 1.6.16 allows context-dependent attackers to execute arbitrary code via IDAT data with a large width, a different vulnerability than CVE-2014-9495.
Apple Security Advisory 2016-03-21-5 - OS X El Capitan 10.11.4 and Security Update 2016-002 is now available and addresses code execution, memory corruption, and various other vulnerabilities.