Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.6.37, a Stored XSS vulnerability was discovered in Open-WebUI's Notes PDF download functionality. An attacker can import a Markdown file containing malicious SVG tags into Notes, allowing them to execute arbitrary JavaScript code and steal session tokens when a victim downloads the note as PDF. This vulnerability can be exploited by any authenticated user, and unauthenticated external attackers can steal session tokens from users (both admin and regular users) by sharing specially crafted markdown files. This vulnerability is fixed in 0.6.37.