Which versions of Discourse are affected by CVE-2025-54411?

CVE-2025-54411 is a low-severity vulnerability in Discourse involving cross-site scripting (CVSS 2.4).. A patch is available.

How to fix or mitigate CVE-2025-54411?

During next maintenance window: Apply vendor patches when convenient. Verify cross-site scripting controls are in place.

Discourse CVE-2025-54411

Q: What is the CVSS score of CVE-2025-54411?

CVE-2025-54411 has a CVSS 4.0 base score of 2.4 (Low). CVSS vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

LOW

Cross-site Scripting (XSS) (CWE-79)

2025-08-19 security-advisories@github.com

XSS Discourse

2.4

CVSS 4.0 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

2.4 LOW

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

Scope

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 19:07 vuln.today

Patch released

Mar 28, 2026 - 19:07 nvd

Patch available

CVE Published

Aug 19, 2025 - 17:15 nvd

LOW 2.4

DescriptionGitHub Advisory

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.

AnalysisAI

Discourse is an open-source discussion platform. Rated low severity (CVSS 2.4), this vulnerability is low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.

Technical ContextAI

This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. 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 include: Discourse.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.