CVE 2007-5715
DenyHosts 2.6 processes OpenSSH sshd "not listed in AllowUsers" log messages with an incorrect regular expression that does not match an IP address, which might allow remote attackers to avoid detection and blocking when making invalid login attempts with a username not present in AllowUsers, as demonstrated by the root username, a different vulnerability than CVE-2007-4323.
See the
CVE page on Mitre.org
for more details.