mkdocs-include-markdown-plugin susceptible to unvalidated input colliding with substitution placeholders

mkdocs-include-markdown-plugin is an Mkdocs Markdown includer plugin. In versions 7.1.7 and below, there is a vulnerability where unvalidated input can collide with substitution placeholders. This issue is fixed in version 7.1.8.

The mkdocs 1.2.2 built-in dev-server allows directory traversal using the port 8000, enabling remote exploitation to obtain :sensitive information. NOTE: the vendor has disputed this as described in https://github.com/mkdocs/mkdocs/issues/2601.] and https://github.com/nisdn/CVE-2021-40978/issues/1