How severe is CVE-2026-26352?

CVE-2026-26352 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-26352 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-26352?

CVE-2026-26352 primarily affects Smoothwall Smoothwall Express. In total, 13 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-26352?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-26352 have an EU (EUVD) identifier?

Yes. CVE-2026-26352 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17126.

When was CVE-2026-26352 published?

CVE-2026-26352 was published on 2026-03-30 and last updated on 2026-06-17.

CVE-2026-26352

CVE-2026-26352 is a medium-severity vulnerability in Smoothwall Smoothwall Express with a CVSS 3.x base score of 5.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v4: 5.1
EPSS exploit prediction: 0% (4th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-17126
Weakness: CWE-79
Affected product: Smoothwall Smoothwall Express
Published: 2026-03-30
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-26352?: CVE-2026-26352 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-26352 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-26352?: CVE-2026-26352 primarily affects Smoothwall Smoothwall Express. In total, 13 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-26352?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-26352 have an EU (EUVD) identifier?: Yes. CVE-2026-26352 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17126.
When was CVE-2026-26352 published?: CVE-2026-26352 was published on 2026-03-30 and last updated on 2026-06-17.

References

Affected products (13)

cpe:2.3:o:smoothwall:smoothwall_express:*:*:*:*:*:*:*:*
cpe:2.3:o:smoothwall:smoothwall_express:3.1:update1:*:*:-:*:*:*
cpe:2.3:o:smoothwall:smoothwall_express:3.1:update10:*:*:-:*:*:*
cpe:2.3:o:smoothwall:smoothwall_express:3.1:update11:*:*:-:*:*:*
cpe:2.3:o:smoothwall:smoothwall_express:3.1:update12:*:*:-:*:*:*
cpe:2.3:o:smoothwall:smoothwall_express:3.1:update2:*:*:-:*:*:*
cpe:2.3:o:smoothwall:smoothwall_express:3.1:update3:*:*:-:*:*:*
cpe:2.3:o:smoothwall:smoothwall_express:3.1:update4:*:*:-:*:*:*
cpe:2.3:o:smoothwall:smoothwall_express:3.1:update5:*:*:-:*:*:*
cpe:2.3:o:smoothwall:smoothwall_express:3.1:update6:*:*:-:*:*:*
cpe:2.3:o:smoothwall:smoothwall_express:3.1:update7:*:*:-:*:*:*
cpe:2.3:o:smoothwall:smoothwall_express:3.1:update8:*:*:-:*:*:*
cpe:2.3:o:smoothwall:smoothwall_express:3.1:update9:*:*:-:*:*:*

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