Integer overflow in the zipcdirnew function in zipdirent.c in libzip 0.11.2 and earlier, as used in the ZIP extension in PHP before 5.4.39, 5.5.x before 5.5.23, and 5.6.x before 5.6.7 and other products, allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a ZIP archive that contains many entries, leading to a heap-based buffer overflow.