net/url in Go before 1.11.13 and 1.12.x before 1.12.8 mishandles malformed hosts in URLs, leading to an authorization bypass in some applications. This is related to a Host field with a suffix appearing in neither Hostname() nor Port(), and is related to a non-numeric port number. For example, an attacker can compose a crafted javascript:// URL that results in a hostname of google.com.
https://www.debian.org/security/2019/dsa-4503
https://seclists.org/bugtraq/2019/Aug/31
https://groups.google.com/forum/#%21topic/golang-announce/65QixT3tcmg
https://groups.google.com/forum/#%21topic/golang-announce/0uuMm1BwpHE
https://github.com/golang/go/issues/29098
https://access.redhat.com/errata/RHSA-2019:3433
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00038.html
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00021.html
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00011.html
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00002.html
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00076.html