The canonicalize_username function in svnserve/cyrus_auth.c in Apache Subversion before 1.8.16 and 1.9.x before 1.9.4, when Cyrus SASL authentication is used, allows remote attackers to authenticate and bypass intended access restrictions via a realm string that is a prefix of an expected repository realm string.
http://lists.fedoraproject.org/pipermail/package-announce/2016-May/184545.html
http://lists.opensuse.org/opensuse-updates/2016-05/msg00043.html
http://lists.opensuse.org/opensuse-updates/2016-05/msg00044.html
https://security.gentoo.org/glsa/201610-05
http://subversion.apache.org/security/CVE-2016-2167-advisory.txt
https://www.oracle.com/security-alerts/cpuoct2020.html