CVE-2023-53904 — Xenforo 2

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 pa

01What is this vulnerability?

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.

02Affected products

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2025-12-17T22:44:43.890Z
• Last modified: 2026-03-05T12:02:51.925Z

09References

• www.exploit-db.com — https://www.exploit-db.com/exploits/51547
• xenforo.com — https://xenforo.com/
• www.vulncheck.com — https://www.vulncheck.com/advisories/xenforo-authenticated-stored-cross-site-scr…