CVE-2026-27508: 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 5% 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:N/UI:A/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, avoid clicking suspicious links involving the /redirect.cgi endpoint and consider implementing web filtering or input validation controls if possible.
Description
Smoothwall Express versions prior to 3.1 Update 13 contain a reflected cross-site scripting vulnerability in the /redirect.cgi endpoint due to improper sanitation of the url parameter. Attackers can craft malicious URLs with javascript: schemes that execute arbitrary JavaScript in victims' browsers when clicked through the unsanitized link.