The bzread function in ext/bz2/bz2.c in PHP before 5.5.38, 5.6.x before 5.6.24, and 7.x before 7.0.9 allows remote attackers to cause a denial of service (out-of-bounds write) or execute arbitrary code via a crafted bz2 archive. https://nvd.nist.gov/vuln/detail/CVE-2016-5399