Security readout for executives and security teams
Plain-English summary
An authenticated user can save malicious script content in Smoothwall Express VPN settings. The script runs when another user views the affected administration page, potentially exposing information or allowing actions in that user’s browser session. The issue affects releases before 3.1 Update 13.
Executive priority
Schedule remediation promptly within the normal medium-severity cycle. Accelerate action for internet-accessible administration interfaces, environments with multiple administrators, or suspected account compromise. The available evidence does not support emergency treatment based on active exploitation.
Technical view
Improper sanitization of the VPN_IP parameter in /cgi-bin/vpnmain.cgi permits stored cross-site scripting. Exploitation requires authenticated access and a victim viewing the stored content. The CVSS 3.1 score is 5.4; expected impact is limited confidentiality and integrity loss, with no stated availability impact.
Likely exposure
Exposure is limited to Smoothwall Express installations earlier than 3.1 Update 13 where an attacker has authenticated access to VPN configuration and another user later views the affected page. Internet-accessible or shared-administration deployments warrant faster review.
Exploitation context
The source bundle marks this CVE as absent from KEV and provides no evidence of active exploitation. Exploitation requires low privileges and user interaction, but the browser security scope changes because injected script executes in another user’s session.
Researcher notes
The narrative and title identify versions before 3.1 Update 13 as affected. However, the supplied structured affected entry lists version "0" with default status "unaffected," creating a data-quality inconsistency. Confirm precise version applicability against the vendor advisory before final asset disposition.
Mitigation direction
- Apply Smoothwall Express 3.1 Update 13 according to the vendor advisory.
- Restrict VPN administration access to trusted users until updating is complete.
- Review VPN configuration data for unexpected or script-like content.
- Consult current Smoothwall guidance if Update 13 cannot be applied promptly.
Validation and detection
- Confirm the installed Smoothwall Express release is 3.1 Update 13.
- Inventory systems exposing the Smoothwall administration interface.
- Review account access and VPN configuration changes for unauthorized activity.
- Verify stored VPN_IP values are safely rendered after remediation.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-26352 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N2.32.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N——VulnCheckVulnerability scoring details
Base CVSS 4.0 score
5.1MediumVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Base CVSS 3.1 score
5.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://community.smoothwall.org/forum/viewtopic.php?t=45095CVE reference, VulnCheck · vendor-advisory, patch
- https://www.vulncheck.com/advisories/smoothwall-express-stored-xss-in-vpnmain-cgi-via-vpn-ip-parameterCVE reference, VulnCheck · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.