The exif_process_IFD_in_TIFF function in ext/exif/exif.c in PHP before 5.6.25 and 7.x before 7.0.10 mishandles the case of a thumbnail offset that exceeds the file size, which allows remote attackers to obtain sensitive information from process memory via a crafted TIFF image.
http://openwall.com/lists/oss-security/2016/09/02/9
http://rhn.redhat.com/errata/RHSA-2016-2750.html
https://bugs.php.net/bug.php?id=72627
https://github.com/php/php-src/commit/6dbb1ee46b5f4725cc6519abf91e512a2a10dfed?w=1
https://security.gentoo.org/glsa/201611-22
https://www.tenable.com/security/tns-2016-19
http://www.php.net/ChangeLog-5.php