Forgejo before 15.0.3 contains a stored cross-site scripting vulnerability that allows authenticated attackers to execute arbitrary JavaScript in other users' browsers by setting a full name containing an HTML payload and triggering an Actions run. When the DEFAULT_SHOW_FULL_NAME option is enabled, the run description is assembled server-side with the user's display name interpolated into an HTML string via a translation function that does not escape its arguments, and the frontend renders the result using a Vue v-html binding, causing script execution for any user who views the affected Actions run page.