HedgeDoc is a platform to write and share markdown. In versions prior to 1.9.0, an unauthenticated attacker can inject arbitrary JavaScript into the speaker-notes of the slide-mode feature by embedding an iframe hosting the malicious code into the slides or by embedding the HedgeDoc instance into another page. The problem is patched in version 1.9.0. There are no known workarounds aside from upgrading.
Smarty is a template engine for PHP, facilitating the separation of presentation (HTML/CSS) from application logic. Prior to versions 3.1.42 and 4.0.2, template authors could run arbitrary PHP code by crafting a malicious math string. If a math string was passed through as user provided data to the math function, external users could run arbitrary PHP code by crafting a malicious math string. Users should upgrade to version 3.1.42 or 4.0.2 to receive a patch.