In PHP through 5.6.33, 7.0.x before 7.0.28, 7.1.x through 7.1.14, and 7.2.x through 7.2.2, there is a stack-based buffer under-read while parsing an HTTP response in the php_stream_url_wrap_http_ex function in ext/standard/http_fopen_wrapper.c. This subsequently results in copying a large string.

An issue was discovered in PHP 7.3.x before 7.3.0alpha3, 7.2.x before 7.2.8, and before 7.1.20. The php-fpm master process restarts a child process in an endless loop when using program execution functions (e.g., passthru, exec, shell_exec, or system) with a non-blocking STDIN stream, causing this master process to consume 100% of the CPU, and consume disk space with a large volume of error logs, as demonstrated by an attack by a customer of a shared-hosting facility.

An issue was discovered in PHP before 5.6.33, 7.0.x before 7.0.27, 7.1.x before 7.1.13, and 7.2.x before 7.2.1. There is Reflected XSS on the PHAR 404 error page via the URI of a request for a .phar file.

gd_gif_in.c in the GD Graphics Library (aka libgd), as used in PHP before 5.6.33, 7.0.x before 7.0.27, 7.1.x before 7.1.13, and 7.2.x before 7.2.1, has an integer signedness error that leads to an infinite loop via a crafted GIF file, as demonstrated by a call to the imagecreatefromgif or imagecreatefromstring PHP function. This is related to GetCode_ and gdImageCreateFromGifCtx.

In PHP before 5.6.32, 7.x before 7.0.25, and 7.1.x before 7.1.11, an error in the date extension's timelib_meridian handling of 'front of' and 'back of' directives could be used by attackers able to supply date strings to leak information from the interpreter, related to ext/date/lib/parse_date.c out-of-bounds reads affecting the php_parse_date function. NOTE: this is a different issue than CVE-2017-11145.

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.

The zend_string_extend function in Zend/zend_string.h in PHP through 7.1.5 does not prevent changes to string objects that result in a negative length, which allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact by leveraging a script's use of .= with a long string.

ext/libxml/libxml.c in PHP before 5.5.22 and 5.6.x before 5.6.6, when PHP-FPM is used, does not isolate each thread from libxml_disable_entity_loader changes in other threads, which allows remote attackers to conduct XML External Entity (XXE) and XML Entity Expansion (XEE) attacks via a crafted XML document, a related issue to CVE-2015-5161.

The pcre_compile2 function in pcre_compile.c in PCRE 8.38 mishandles the /((?:F?+(?:^(?(R)a+\"){99}-))(?J)(?'R'(?'R'<((?'RR'(?'R'\){97)?J)?J)(?'R'(?'R'\){99|(:(?|(?'R')(\k'R')|((?'R')))H'R'R)(H'R))))))/ pattern and related patterns with named subgroups, which allows remote attackers to cause a denial of service (heap-based buffer overflow) or possibly have unspecified other impact via a crafted regular expression, as demonstrated by a JavaScript RegExp object encountered by Konqueror.