Updated poppler packages has been released for Debian GNU/Linux 7 LTS

Package : poppler
Version : 0.18.4-6+deb7u5
CVE ID : CVE-2017-1000456

Jason Crain discovered a overflow vulnerability in the poppler PDF
rendering library.

For Debian 7 "Wheezy", this issue has been fixed in poppler version
0.18.4-6+deb7u5.

We recommend that you upgrade your poppler packages.