XSS in Xenforo

CVE-2023-53904

Xenforo 2.2.13 contains a stored cross-site scripting vulnerability that allows authenticated administrators to inject malicious scripts through the smilie category title parameter. Attackers can create a smilie category with a malicious script that will execute when the admin panel is loaded, potentially enabling further client-side attacks.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.6 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (17.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 17.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2023-53904: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-53904?
CVE-2023-53904 is a medium-severity vulnerability in Xenforo, classified under Cross-site Scripting. CVSS score: 4.6/10. Published 2025-12-17.
How severe is CVE-2023-53904?
Medium severity. CVSS v3 base score is 4.6 out of 10.