Versions 1.4.0 and earlier of remarkable are affected by a cross-site scripting vulnerability. This occurs because vulnerable versions of remarkable did not properly deny link protocols, and consequently allowed javascript: to be used.

Proof of Concept

Markdown Source:

[link](<javascript:alert(1)>)

Rendered HTML:

<a href="javascript:alert(1)">link</a>

Update to version 1.4.1 or later