libssh before 0.7.3 improperly truncates ephemeral secrets generated for the (1) diffie-hellman-group1 and (2) diffie-hellman-group14 key exchange methods to 128 bits, which makes it easier for man-in-the-middle attackers to decrypt or intercept SSH sessions via unspecified vectors, aka a “bits/bytes confusion bug.”
lists.fedoraproject.org/pipermail/package-announce/2016-February/178058.html
lists.fedoraproject.org/pipermail/package-announce/2016-March/178822.html
lists.opensuse.org/opensuse-updates/2016-03/msg00111.html
rhn.redhat.com/errata/RHSA-2016-0566.html
www.debian.org/security/2016/dsa-3488
www.ubuntu.com/usn/USN-2912-1
puppet.com/security/cve/CVE-2016-0739
security.gentoo.org/glsa/201606-12
www.libssh.org/2016/02/23/libssh-0-7-3-security-and-bugfix-release/
www.libssh.org/security/advisories/CVE-2016-0739.txt