Several security issues were fixed in libpng.
Patrick Keshishian discovered that libpng incorrectly handled certain PNG files. An attacker could possibly use this to cause a denial of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2016-10087)
11 July 2018
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in libpng.
Patrick Keshishian discovered that libpng incorrectly handled certain PNG files. An attacker could possibly use this to cause a denial of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2016-10087)
Thuan Pham discovered that libpng incorrectly handled certain PNG files. An attacker could possibly use this to cause a denial of service. This issue only affected Ubuntu 17.10 and Ubuntu 18.04 LTS. (CVE-2018-13785)
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.