Again a flaw (Stack Clash) has been identified in versions of Linux, mainly BSDs but also others. This a stack overflaw type of flaw that can lead to privileges escalation and remote exploit.
Please make sure to apply any security update in the next days to protect yourselves 
More details (in french sorry): https://www.nextinpact.com/news/104609-stack-clash-importante-faille-securite-pour-systemes-unix-et-derives.htm