The caddy-security plugin 1.1.20 for Caddy allows reflected XSS via a GET request to a URL that contains an XSS payload and begins with either a /admin or /settings/mfa/delete/ substring.
https://github.com/greenpau/caddy-security/issues/264
https://blog.trailofbits.com/2023/09/18/security-flaws-in-an-sso-plugin-for-caddy/