XenForo up to 2.3.8 BB Code Rendering cross site scripting

CVSS Meta Temp Score
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CTI Interest Score
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4.9$0-$5k0.33-

Summaryinfo

A vulnerability has been found in XenForo up to 2.3.8 and classified as problematic. The affected element is an unknown function of the component BB Code Rendering. Performing a manipulation results in cross site scripting. This vulnerability is known as CVE-2026-35054. Remote exploitation of the attack is possible. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in XenForo up to 2.3.8. It has been classified as problematic. This affects an unknown part of the component BB Code Rendering. The manipulation with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. The summary by CVE is:

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.

The weakness was published by Antisocial. The advisory is shared at xenforo.com. This vulnerability is uniquely identified as CVE-2026-35054 since 04/01/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

Upgrading to version 2.3.9 eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.9
VulDB Meta Temp Score: 4.9

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.4
CNA Vector (VulnCheck): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: XenForo 2.3.9

Timelineinfo

04/01/2026 Advisory disclosed
04/01/2026 +0 days CVE reserved
04/01/2026 +0 days VulDB entry created
04/01/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: xenforo.com
Researcher: Antisocial
Status: Confirmed

CVE: CVE-2026-35054 (🔒)
GCVE (CVE): GCVE-0-2026-35054
GCVE (VulDB): GCVE-100-354525

Entryinfo

Created: 04/01/2026 04:08
Changes: 04/01/2026 04:08 (76)
Complete: 🔍
Cache ID: 216:12E:103

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