Apache HTTP Server versions 2.4.0 through 2.4.39 are vulnerable to a limited cross-site scripting issue affecting the mod_proxy error page. An attacker could cause the link on the error page to be malformed and instead point to a page of their choice. This would only be exploitable where a server was set up with proxying enabled but was misconfigured in such a way that the Proxy Error page was displayed.
View the template here CVE-2019-10092.yaml
References:
https://github.com/DrunkenShells/Disclosures/tree/master/CVE-2019-10092-Limited%20Cross-Site%20Scripting%20in%20mod_proxy%20Error%20Page-Apache%20httpd