K-Box is a web-based application to manage documents, images, videos and geodata. Prior to version 0.33.1, a stored Cross-Site-Scripting (XSS) vulnerability is present in the markdown editor used by the document abstract and markdown file preview. A specifically crafted anchor link can, if clicked, execute untrusted javascript actions, like retrieving user cookies. Version 0.33.1 includes a patch that allows discarding unsafe links.