What is CVE-2026-26352?

CVE-2026-26352 is a medium-severity vulnerability in Smoothwall Express, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-03-30.

How severe is CVE-2026-26352?

Medium severity. CVSS v3 base score is 5.4 out of 10.

XSS in Smoothwall Express

CVE-2026-26352

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.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.001 (3.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

Affected products

Smoothwall Express — versions 0
Smoothwall Smoothwall_express — versions 3.1

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

disclosure@vulncheck.com (Product, vendor-advisory, Release Notes, patch)
disclosure@vulncheck.com (Third Party Advisory, third-party-advisory)

Frequently asked questions

What is CVE-2026-26352?: CVE-2026-26352 is a medium-severity vulnerability in Smoothwall Express, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-03-30.
How severe is CVE-2026-26352?: Medium severity. CVSS v3 base score is 5.4 out of 10.