CVE-2026-35054

XenForo Stored Cross-Site Scripting via BB Code Rendering

5.1 Medium

XenForo before 2.3.9 is vulnerable to stored cross-site scripting (XSS) related to BB code rendering. An attacker can inject malicious scripts through BB code that are stored and executed when other users view the content.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: Passive

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: None

Exploit likelihood

0.14%Up 0.1 points since Apr 1, 2026

What each source reports

CVE List Score used 5.1

XenForo Stored Cross-Site Scripting via BB Code Rendering

Record: CVE-2026-35054
CVSS 4.0: 5.1 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
CVSS 3.1: 6.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

EUVDEUVD-2026-17739 5.1

Record: EUVD-2026-17739
CVSS 4.0: 5.1 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-2ch2-j7qp-pqm3 5.1

XenForo before 2.3.9 is vulnerable to stored cross-site scripting (XSS) related to BB code...

Record: GHSA-2ch2-j7qp-pqm3
CVSS 4.0: 5.1 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/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
CVSS 3.1: 6.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

NVD 5.1

Record: CVE-2026-35054
CVSS 4.0: 5.1 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/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
CVSS 3.1: 6.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
CVSS 3.1: 5.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

Affected products

xenforo

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-35054 is a medium vulnerability (CVSS 5.1) in Xenforo, published April 1, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.14%, the 3rd percentile. No source names a fixed version.