Write to [email protected] with what you found and how to reproduce it. You will get a reply from the person who wrote the code, a fix, and credit if you want it. Please give us a reasonable time to fix a problem before publishing it.
lapstack runs on your own machine — in a browser tab, as a desktop application, or as a command-line tool — and makes no network requests of its own, so the surface is the files it reads and writes. A crafted image or raw file that crashes it or makes it misbehave is the kind of report this address is for; so is anything on lapstack.ragtux.com or lapstack.app.ragtux.com.
/.well-known/security.txt on both hosts says the same.