---
id: CVE-2025-34237
title: "Advantech WebAccess/VPN versions prior to 1.1.5 contain a stored cross-site scripting (XSS) vulnerability via\_StandaloneVpnClientsController.addStandaloneVpnClientAction()"
summary: "Advantech WebAccess/VPN versions prior to 1.1.5 contain a stored cross-site scripting (XSS) vulnerability via\_StandaloneVpnClientsController.addStandaloneVpnClientAction(). Insufficient validation or escaping of user-supplied input may a…"
severity: medium
cvss: 5.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
vendor: advantech
product: webaccess/vpn
affected:
  - webaccess/vpn < 1.1.5
patched:
  - webaccess/vpn 1.1.5
published: '2025-11-06'
updated: '2026-10-07'
sourceUpdated: '2026-10-07T21:10:00.200'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-34237'
references:
  - url: 'https://icr.advantech.com/download/software'
    label: disclosure@vulncheck.com
  - url: >-
      https://icr.advantech.com/support/router-models/download/511/sa-2025-01-vpn-portal-2025-11-06.pdf
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/advantech-webaccess-vpn-stored-xss-via-standalonevpnclientscontroller
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00216
epssPercentile: 0.11025
ingestedAt: '2026-10-07T21:54:14.966Z'
---

## Overview

Advantech WebAccess/VPN versions prior to 1.1.5 contain a stored cross-site scripting (XSS) vulnerability via StandaloneVpnClientsController.addStandaloneVpnClientAction(). Insufficient validation or escaping of user-supplied input may allow an attacker to inject and execute arbitrary script in the context of a victim's browser.

## Affected

- `webaccess/vpn < 1.1.5`

## Remediation

Upgrade past the affected range:

- `webaccess/vpn 1.1.5`