maildev is vulnerable to Remote Code Execution. The vulnerability is due to insufficient input validation and sanitization of crafted Content-ID header for an e-mail attachment, resulting in lib/mailserver.js writing arbitrary code into the routes.js file.
gist.github.com/stypr/fe2003f00959f7e3d92ab9d5260433f8
github.com/advisories/GHSA-vc6q-ccj9-9r89
github.com/maildev/maildev/commit/f4afcd984dbf48f81a535f004e775093fe4c50fe
github.com/maildev/maildev/issues/467
github.com/maildev/maildev/releases
github.com/Tim-Hoekstra/MailDev-2.1.0-Exploit-RCE
intrix.com.au/articles/exposing-major-security-flaw-in-maildev