At the MySQL 5.5.52 Release Notes i see that the security problem should got fixed in the 5.5.52 release:
For mysqld_safe, the argument to --malloc-lib now must be one of the directories /usr/lib, /usr/lib64, /usr/lib/i386-linux-gnu, or /usr/lib/x86_64-linux-gnu. In addition, the --mysqld and --mysqld-version options can be used only on the command line and not in an option file. (Bug #24464380)
I am unsure if i am affected or not, the exact installed version on my server, which is running on CentOS 6, is
mysql-5.5.52-36.el6.art.x86_64 from the webtatic repo.
The paper on legalhackers.com from Dawid Golunski, which had found that issue, does not list my mysql version.