Mozilla Firefox before 38.0 does not recognize a referrer policy delivered by a referrer META element in cases of context-menu navigation and middle-click navigation, which allows remote attackers to obtain sensitive information by reading web-server Referer logs that contain private data in a URL, as demonstrated by a private path component.
http://lists.opensuse.org/opensuse-updates/2015-05/msg00036.html
http://www.mozilla.org/security/announce/2015/mfsa2015-49.html
http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
http://www.securityfocus.com/bid/74611
http://www.ubuntu.com/usn/USN-2602-1