Open JDK 8 will be updated in 18.04 until Ubuntu 16.04 LTS reaches EOL in April 2021.
The default Open SSL has been upgraded from 1.1.0 to 1.1.1 LTS series bringing improved performance and ability to use TLSv1.3 in select packages.
Adobe Flash Player is a multimedia platform used to add animation, video, and interactivity to Web pages.
Flash is frequently used for advertisements and games.
However, we cannot modify the Adobe Flash Player to fix problems in Debian.
So if you find a problem with the Adobe Flash Player, then please report it to Adobe.
These release notes for Ubuntu 18.04.3 LTS (Bionic Beaver) provide an overview of the release and document the known issues with Ubuntu 18.04 LTS and its flavors.
The 'main' archive of Ubuntu 18.04 LTS will be supported for 5 years until April 2023.
Since fully utilizing these mitigations needs more than just an upgrade, it is recommended to read details at the blog post.