ext/standard/var_unserializer.re in PHP 7.0.x through 7.0.22 and 7.1.x through 7.1.8 is prone to a heap use after free while unserializing untrusted data, related to improper use of the hash API for key deletion in a situation with an invalid array size. Exploitation of this issue can have an unspecified impact on the integrity of PHP.
php.net/ChangeLog-7.php
www.securityfocus.com/bid/100427
access.redhat.com/errata/RHSA-2018:1296
access.redhat.com/errata/RHSA-2019:2519
bugs.php.net/bug.php?id=74103
github.com/php/php-src/commit/1a23ebc1fff59bf480ca92963b36eba5c1b904c4
security.gentoo.org/glsa/201709-21
security.netapp.com/advisory/ntap-20180112-0001/
www.debian.org/security/2018/dsa-4080