Hello Eric, The last version of firmware for the FS8600 is 6.0.3.  Your FS8600 is not affected this CVE. Please let us know if you have any other questions.
Is the FS8600 vulnerable to Samba Security Updates CVE-2019-3870 and CVE-2019-3880 & what's the latest firmware available for the FS8600?   Thanks!Eric  
Is the FS8600 vulnerable to Samba Security Updates CVE-2019-3870 and 
CVE-2019-3880