Medium · published August 22, 2026
Typemill is a flat-file, Markdown-based content management system designed for informational documentation websites. Versions prior to 2.23.0 are vulnerable to stored HTML attribute injection in the page metadata fields (`og:title` and `og:description`). An authenticated user with permission to modify page metadata can inject arbitrary HTML attributes into generated `<meta>` tags due to missing output encoding. Under certain browser or DOM interaction scenarios, this may lead to stored cross-site scripting (XSS). Version 2.23.0 fixes the issue.