A path traversal exists in markdown-pdf version <9.0.0 that allows a user to insert a malicious html code that can result in reading the local files.
https://github.com/CQ-Tools/CVE-2018-3770-unfixed
https://github.com/CQ-Tools/CVE-2018-3770-fixed
https://github.com/advisories/GHSA-p7c9-jqhq-vr3v