Medium severity · published Mar 30, 2026
CVE-2026-26352
Smoothwall Express < 3.1 Update 13 Stored XSS in vpnmain.cgi via VPN_IP Parameter
5.4
CVSS
0.1%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 4% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EX
Express · Smoothwall
before 3.1 Update 13 · source: vendor
SE
Smoothwall Express · Smoothwall
through 3.0; 3.1; 3.1; 3.1; 3.1; 3.1; +7 more · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-26352
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-26352
Product
https://community.smoothwall.org/forum/viewtopic.php?t=45095
Third Party Advisory
https://www.vulncheck.com/advisories/smoothwall-express-stored-xss-in-vpnmain-cgi-via-vpn-ip-parameter
More from Express
6.1
CVE-2026-27508
Smoothwall Express < 3.1 Update 13 Reflected XSS in redirect.cgi via url Parameter