High · published August 27, 2026
Penpot is an open-source design and prototyping platform. In versions up to and including 2.14.3, Penpot is vulnerable to stored cross-site scripting through file comments, whose content is stored as raw text and rendered into the page with innerHTML without any sanitization. Because the backend applies only a length check and the frontend writes comment content directly through innerHTML, any team member who can comment on a shared file can embed HTML such as an image error handler or script that executes in the browser of every other collaborator. The attack is passive: any user who opens the comments panel on the affected file triggers script execution on the Penpot origin, allowing theft of session cookies, actions performed as the victim, and access to their files and projects. This issue is fixed in version 2.15.3.