GHSA-mqf3-qpc3-g26q: Silverstripe Framework has a Reflected Cross Site Scripting (XSS) in error message

[!IMPORTANT] This vulnerability only affects sites which are in the “dev” environment mode. If your production website is in “dev” mode, it has been misconfigured, and you should immediately swap it to “live” mode. See https://docs.silverstripe.org/en/developer_guides/debugging/environment_types/ for more information.

If a website has been set to the “dev” environment mode, a URL can be provided which includes an XSS payload which will be executed in the resulting error message.