CVE-2026-26352: Smoothwall Express · Cross-site Scripting
Affects Smoothwall ExpressSource CVE Database V5
Not known to be exploited · CVSS 5.1 Medium : upgrade to 3.1 Update 13 when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.1 Update 13
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 30 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade Smoothwall Express to 3.1 Update 13.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| SmoothwallExpress | Affected
| Fixed in
|
AI-suggested
In the meantime, restrict access to the VPN configuration interface to trusted users only and consider additional input validation or filtering controls if possible.
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.