Medium 6.1Published Mar 31, 2026

CVE-2026-35055XenForo Cross-Site Scripting via Lightbox in Posts

Updated under an hour ago (Oct 27, 2026, 10:40 PM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

XenForo before 2.3.9 and before 2.2.18 is vulnerable to cross-site scripting (XSS) related to lightbox usage in posts. An attacker can inject malicious scripts that execute when users interact with post content displayed in the lightbox.

CVSS: 6.1 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weakness (CWE): CWE-79
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: VulnCheck
NVD analysis: Analyzed
Record last updated: May 23, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

XenForo XenForo xenforo:xenforo (from the name)	from 2.3.0 before 2.3.9; before 2.2.18	CNA record
xenforo xenforo xenforo:xenforo	before 2.2.18; from 2.3.0 before 2.3.9	NVD

References

References

https://xenforo.com/community/threads/xenforo-2-3-9-inc-xfmg-2-2-18-released-security-fix.235659/	vendor-advisory, patch, release-notes
https://www.vulncheck.com/advisories/xenforo-cross-site-scripting-via-lightbox-in-posts	third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.