Go before 1.14.8 and 1.15.x before 1.15.1 allows XSS because text/html is the default for CGI/FCGI handlers that lack a Content-Type header.
lists.opensuse.org/opensuse-security-announce/2020-10/msg00000.html
lists.opensuse.org/opensuse-security-announce/2020-10/msg00002.html
packetstormsecurity.com/files/159049/Go-CGI-FastCGI-Transport-Cross-Site-Scripting.html
seclists.org/fulldisclosure/2020/Sep/5
groups.google.com/forum/#%21topic/golang-announce/8wqlSbkLdPs
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CZBO7Q73GGWBVYIKNH2HNN44Q5IQND5W/
security.netapp.com/advisory/ntap-20200924-0003/
www.oracle.com//security-alerts/cpujul2021.html
www.oracle.com/security-alerts/cpuApr2021.html
www.redteam-pentesting.de/advisories/rt-sa-2020-004