Only the latest version of the Firefly III CSV importer is supported. If you're not running the latest version of the Firefly III CSV importer, please upgrade at your earliest convenience.
If you find something that compromises the security of the Firefly III CSV importer, you should send me a message as soon as possible. These issues will be fixed immediately. You can also open an issue, but if you feel the issue is sensitive, please drop me a message instead.
You can use my GPG key for extra security. My GitHub commits are almost always signed with this key.