FFmpeg 2.x allows remote attackers to conduct cross-origin attacks and read arbitrary files by using the concat protocol in an HTTP Live Streaming (HLS) M3U8 file, leading to an external HTTP request in which the URL string contains the first line of a local file.
https://www.kb.cert.org/vuls/id/772447
https://security.gentoo.org/glsa/201705-08
https://security.gentoo.org/glsa/201606-09
http://www.ubuntu.com/usn/USN-2944-1
http://www.slackware.com/security/viewer.php?l=slackware-security&y=2016&m=slackware-security.529036
http://www.securitytracker.com/id/1034932
http://www.securityfocus.com/bid/80501
http://www.openwall.com/lists/oss-security/2016/01/14/1
http://www.debian.org/security/2016/dsa-3506
http://lists.opensuse.org/opensuse-security-announce/2016-01/msg00034.html