[ https://issues.jboss.org/browse/WFLY-10648?page=com.atlassian.jira.plugin... ] Jan Stourac commented on WFLY-10648: ------------------------------------ Note that this starts to work when you percent-encode the curly brackets, so you use: {code} http://localhost:8080?q=%7B%7D {code} on your locally running WildFly (checked with WildFly 15). Although, it looks like common browsers (Firefox, Chrome) don't encode these. Based on [RFC1738|https://tools.ietf.org/html/rfc1738#section-2.2], curly brackets are supposed to be 'unsafe' characters and as such percent-encoded always. Although the RFC1738 has been obsoleted by [RFC3986|https://tools.ietf.org/html/rfc3986] which does not specify in any way. Note there is a workaround to allow unescaped characters in URL for your listener: {code} /subsystem=undertow/server=default-server/http-listener=default:write-attribute(name=allow-unescaped-characters-in-url,value=true) {code} -- This message was sent by Atlassian Jira (v7.12.1#712002)