Wekan is open source kanban built with Meteor. From 8.72 until 10.23, addBoardHTMLToZip() in client/lib/exportHTML.js read a card title and body through textContent, which decoded entity-encoded markup, and then interpolated titleText and allText into content.innerHTML in the exported index.html. A board member could store an entity-encoded event-handler payload in a card title that remained inert on the live board but was reparsed and executed when a recipient clicked the card in the downloaded HTML export, allowing the script to read and transmit all board data contained in that export, including content added after the attacker's membership was removed.
Version 10.23 builds the modal with DOM nodes and assigns untrusted values through textContent. This issue is fixed in version 10.23.
Attack Parameters
Impact Assessment
CVSS Vector v3.1