The keyring DB in GnuPG before 2.1.2 does not properly handle invalid packets, which allows remote attackers to cause a denial of service (invalid read and use-after-free) via a crafted keyring file.
http://www.securitytracker.com/id/1031876
http://www.openwall.com/lists/oss-security/2015/02/14/6
http://www.openwall.com/lists/oss-security/2015/02/13/14