Please update libssh 0.5.3 as soon as possible in all supported Fedora versions!!! http://www.libssh.org/2012/11/20/libssh-0-5-3-security-release/
libssh-0.5.3-1.fc18 has been submitted as an update for Fedora 18. https://admin.fedoraproject.org/updates/libssh-0.5.3-1.fc18
*** This bug has been marked as a duplicate of bug 878521 ***
libssh-0.5.3-1.fc18 has been pushed to the Fedora 18 stable repository. If problems still persist, please make note of it in this bug report.