Time to sudo apt-get update && sudo apt-get upgrade or sudo yum update && sudo yum upgrade.
This exploit allows hackers to further escalate privileges from mysql user to root user and thus allow attackers to fully compromise the target server.
External hackers who pop websites using common vulnerabilities and gain a low-privileged footing could also use the bugs to escalate to god mode.
CVE-2016-6662, CVE-2016-6664