CVE-2025-54411: Discourse

Medium severity, CVSS 5.4. EPSS: 0.2% chance of exploitation in the next 30 days.

Discourse is an open-source discussion platform. Welcome banner user name string for logged in users can be vulnerable to XSS attacks, which affect the user themselves or an admin impersonating them. Admins can temporarily alter the welcome_banner.header.logged_in_members site text to remove the preferred_display_name placeholder, or not impersonate any users for the time being. This vulnerability is fixed in 3.5.0.beta8.

Affected products

• Discourse Discourse: before 3.5.0 (fixed in 3.5.0); version 3.5.0 only

Published 2025-08-19. Last modified 2026-06-17.