The new IcedTea release will build you the latest Java8: OpenJDK 8u232_b09. This release syncs the OpenJDK support in IcedTea to the official October 2019 security fixes that Oracle released for Java. The release announcement in the mailing list for distro packagers has details about all the security issues and vulnerabilities that are addressed.
I have built Slackware packages for the new Java 8 Update 232 and uploaded them already. Please upgrade at your earliest convenience. Java is still widespread which makes it a popular target for vulnerability attacks.
Here is where you can download the Slackware packages for openjdk and openjre:
(rsync also available: rsync://slackware.nl/mirrors/people/alien/slackbuilds/)
If you want to compile OpenJDK 8 yourself you will need apache-ant as well, but otherwise the openjdk/openjre packages have no external dependencies.
Note about usage:
My Java 7 and Java 8 packages (e.g. openjdk7 and openjdk… or openjre7 and openjre) can not co-exist on your computer because they use the same installation directory. You must install either Java 7 or Java 8.
Remember that I release packages for the JRE (runtime environment) and the JDK (development kit) simultaneously, but you only need to install one of the two. The JRE is sufficient if you only want to run Java programs (including Java web plugins). Only in case where you’d want to develop Java programs and need a Java compiler, you are in need of the JDK package.