In Eclipse Jetty versions 9.4.21.v20190926, 9.4.22.v20191022, and 9.4.23.v20191118, the generation of default unhandled Error response content (in text/html and text/json Content-Type) does not escape Exception messages in stacktraces included in error output.
{ "availability": "No subscription required", "ubuntu_priority": "low", "binaries": [ { "binary_version": "9.4.26-1", "binary_name": "jetty9" }, { "binary_version": "9.4.26-1", "binary_name": "libjetty9-extra-java" }, { "binary_version": "9.4.26-1", "binary_name": "libjetty9-java" } ] }