XWiki Contrib's Syntax Markdown allows importing Markdown content into wiki pages and creating wiki content in Markdown. In versions starting from 8.2 to before 8.9, the Markdown syntax is vulnerable to cross-site scripting (XSS) through HTML. In particular, using Markdown syntax, it's possible for any user to embed Javascript code that will then be executed on the browser of any other user visiting either the document or the comment that contains it. In the instance that this code is executed by a user with admins or programming rights, this issue compromises the confidentiality, integrity and availability of the whole XWiki installation. This issue has been patched in version 8.9.

AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

CWE-79

https://github.com/xwiki-contrib/syntax-markdown/commit/d136472d6e8a47981a0ede420a9096f88ffa5035

https://github.com/xwiki-contrib/syntax-markdown/security/advisories/GHSA-8g2j-rhfh-hq3r

https://jira.xwiki.org/browse/MARKDOWN-80