Description
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.
References (2)
Core 2
Core References
Mitigation, Third Party Advisory x_refsource_confirm
https://github.com/discourse/discourse/security/advisories/GHSA-5mm6-j5vq-6884
Scores
CVSS v3
5.4
EPSS
0.0004
EPSS Percentile
11.1%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-79
Status
published
Products (2)
discourse/discourse
3.5.0 beta1 (7 CPE variants)
discourse/discourse
< 3.5.0
Published
Aug 19, 2025
Tracked Since
Feb 18, 2026