VDB-354215 · CVE-2026-26352 · EUVD-2026-17126

Smoothwall Express up to 3.1 Update 12 /cgi-bin/vpnmain.cgi VPN_IP cross site scripting

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
4.4	$0-$5k	2.38+

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Smoothwall Express up to 3.1 Update 12. This issue affects some unknown processing of the file /cgi-bin/vpnmain.cgi. The manipulation of the argument VPN_IP leads to cross site scripting. This vulnerability is referenced as CVE-2026-26352. Remote exploitation of the attack is possible. No exploit is available. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Smoothwall Express up to 3.1 Update 12. This issue affects an unknown functionality of the file /cgi-bin/vpnmain.cgi. The manipulation of the argument VPN_IP with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to 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. Impacted is integrity. The summary by CVE is:

Smoothwall Express versions prior to 3.1 Update 13 contain a stored cross-site scripting vulnerability in the /cgi-bin/vpnmain.cgi script due to improper sanitation of the VPN_IP parameter. Authenticated attackers can inject arbitrary JavaScript through VPN configuration settings that executes when the affected page is viewed by other users.

The weakness was published by Alex Williams. It is possible to read the advisory at community.smoothwall.org. The identification of this vulnerability is CVE-2026-26352 since 02/13/2026. The exploitation is known to be easy. The attack may be initiated remotely. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1059.007 according to MITRE ATT&CK.

Applying the patch 3.1 Update 13 is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-17126). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

Smoothwall

Name

Express

Version

3.1 Update 12

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: 4.4
VulDB Meta Temp Score: 4.4

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

CNA Base Score: 5.4
CNA Vector (VulnCheck): 🔒

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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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
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: 3.1 Update 13

Timelineinfo

02/13/2026 CVE reserved
03/30/2026 +44 days Advisory disclosed
03/30/2026 +0 days VulDB entry created
03/30/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: community.smoothwall.org
Researcher: Alex Williams
Status: Confirmed

CVE: CVE-2026-26352 (🔒)
GCVE (CVE): GCVE-0-2026-26352
GCVE (VulDB): GCVE-100-354215
EUVD: 🔒

Entryinfo

Created: 03/30/2026 19:44
Updated: 03/30/2026 20:18
Changes: 03/30/2026 19:44 (78), 03/30/2026 20:18 (1)
Complete: 🔍
Cache ID: 216:B37:103