Please open an issue to identify any bugs or security vulnerabilities in scrapli. There is a bug report issue template that you can fill out that will help get things rolling!
We will do our best to make any necessary updates to keep scrapli_netconf secure, if there is a known issue/gap, this document will outline the issue and affected version(s) of scrapli_netconf.
scrapli_netconf allows for -- and defaults to -- strict SSH host key checking (though this can be disabled). Strict host key checking can be disabled though, so if that worries you, don't do that! scrapli_netconf does not store any credential information, however of course username/password/etc. is stored in memory when using scrapli_netconf.
At the moment there are no known security gaps/issues. In the future we will try to update this document with any issues and what version of scrapli and any dependencies are affected, however this will all be best effort, and there is are no guarantees/assurance that scrapli is secure; though of course effort is invested to try to make it as secure as possible!