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-2018-20481, CVE-2018-20650)
22 January 2019
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-2018-20481, CVE-2018-20650)
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.