From upcoming https://golang.org/doc/devel/release.html#go1.6.minor
go1.6.3 (released 2016/07/17) includes security fixes to the net/http/cgi
package and net/http package when used in a CGI environment. This release also
adds support for macOS Sierra. See the Go 1.6.3 milestone on our issue
tracker for details.
/reviewed-by TrustMe (tested with helloworld)