Vulnerability in gollum wiki, please update to v4.0.1

[Dawa Ometto]

Hi,

A vulnerability has been found in the gollum wiki, which allows
attackers to gain read access to arbitrary files on the system. Please
update to the gollum 4.0.1 (`gem update gollum`) ASAP. More details will
be posted after a CVE has been assigned.

For more information see https://github.com/gollum/gollum/issues/1070

Thanks in advance,

Dawa Ometto