Several security issues were fixed in poppler.
It was discovered that poppler incorrectly handled certain PDF files. An attacker could possibly use this issue to cause a denial of service. (CVE-2018-16646, CVE-2018-19058, CVE-2018-19059, CVE-2018-19060)
4 December 2018
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in poppler.
It was discovered that poppler incorrectly handled certain PDF files. An attacker could possibly use this issue to cause a denial of service. (CVE-2018-16646, CVE-2018-19058, CVE-2018-19059, CVE-2018-19060)
It was discovered that poppler incorrectly handled certain PDF files. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2018-19149)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.