CVE-2025-54411: discourse XSS — Fix

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.

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CVSS v3.1 Score

5.4

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

Affected Products

Vendor	Product	Versions
discourse	discourse	< 3.5.0
discourse	discourse	All
discourse	discourse	All
discourse	discourse	All
discourse	discourse	All
discourse	discourse	All
discourse	discourse	All
discourse	discourse	All

References

Advisories & Patches

https://github.com/discourse/discourse/commit/a3374d2850f07444d113216e1d539ee21650dbff

Other References

https://github.com/discourse/discourse/security/advisories/GHSA-5mm6-j5vq-6884

Frequently Asked Questions

What is CVE-2025-54411? +

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. It has a CVSS v3.1 base score of 5.4 (MEDIUM).

How severe is CVE-2025-54411? +

CVE-2025-54411 has a CVSS v3.1 score of 5.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-54411? +

CVE-2025-54411 affects products from discourse, specifically: discourse. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-54411? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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