FULL PRODUCT VERSION :
RHEL:
java version "1.8.0_144"
Java (TM) SE Runtime Environment (build 1.8.0_144-b01)
Java HotSpot(TM) 64-Bit Server VM (build 25.144-b01, mixed mode)

Windows:
java 9.0.1
Java(TM) SE Runtime Environment (build 9.0.1+11)
Java HotSpot(TM) 64-Bit Server VM (build 9.0.1+11, mixed mode)



ADDITIONAL OS VERSION INFORMATION :
Windows 7 x64
Red Hat Enterprise Linux Server release 6.8 (Santiago)

A DESCRIPTION OF THE PROBLEM :
Files.probeContentType() will return for a simple CSV file on Linux "text/csv" and on windows "application/vnd.ms-excel"

Probably related to JDK-8186071

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The same return in both scenarios for the same file on either linux or windows.

REPRODUCIBILITY :
This bug can be reproduced always.