CVE-2026-35055

Name: CVE-2026-35055
Creator: NVD / NIST
Published: 2026-04-01T01:16:41.397+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.1/10EPSS 0.15%

Last modified Jun 17, 2026

CVE-2026-35055 is a medium-severity vulnerability rated 5.1/10 on the CVSS scale. 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.. EPSS estimates a 0.15% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

6.1/10

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

CVSS 4.0

5.1/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/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 Probability

0.15%

5.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Xenforo	Xenforo	< 2.2.18
Xenforo	Xenforo	>= 2.3.0, < 2.3.9

References

https://www.vulncheck.com/advisories/xenforo-cross-site-scripting-via-lightbox-in-postsThird Party Advisory
https://xenforo.com/community/threads/xenforo-2-3-9-inc-xfmg-2-2-18-released-security-fix.235659/Release Notes

Timeline

Published: Apr 1, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-35055?

How severe is CVE-2026-35055?

CVE-2026-35055 has a CVSS score of 5.1/10 (MEDIUM severity). The EPSS model estimates a 0.15% probability of exploitation in the next 30 days.

How do I fix CVE-2026-35055?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-35055?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST