In Wiki.js before 2.4.107, there is a stored cross-site scripting through template injection. This vulnerability exists due to an insecure validation mechanism intended to insert v-pre tags into rendered HTML elements which contain curly-braces. By creating a crafted wiki page, a malicious Wiki.js user may stage a stored cross-site scripting attack. This allows the attacker to execute malicious JavaScript when the page is viewed by other users. This has been patched in 2.4.107.
In Wiki.js before 2.3.81, there is a stored XSS in the Markdown editor. An editor with write access to a page, using the Markdown editor, could inject an XSS payload into the content. If another editor (with write access as well) load the same page into the Markdown editor, the XSS payload will be executed as part of the preview panel. The rendered result does not contain the XSS payload as it is stripped by the HTML Sanitization security module. This vulnerability only impacts editors loading the malicious page in the Markdown editor. This has been patched in 2.3.81.