What happened
Typemill CMS version 2.x contains a persistent cross-site scripting vulnerability in the Markdown parser extension that allows authenticated users with theme-configuration access to inject malicious JavaScript URIs by supplying unsanitized href values in Markdown links. Attackers can craft Markdown links using the javascript: scheme through ParsedownExtension.php or TwigMarkdownExtension.php, storing a persistent payload that executes in the browser of every visitor who clicks the link, enabling session cookie theft, authenticated request forgery, and credential harvesting.
Affected versions
Typemill: 2.0.0 through 2.23.0 (semver) Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.