CVE-2025-34236: Advantech WebAccess/VPN · XSS or 'Cross-site Scripting'
Affects Advantech WebAccess/VPNSource CVE Database V5
Not known to be exploited · CVSS 6.2 Medium.
Data as of 26 Oct 2026, 09:15 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 6 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Advantech WebAccess/VPN | Affected
| Fixed in– |
AI-suggested
European organizations should implement the following specific mitigations: 1) Upgrade Advantech WebAccess/VPN to version 1.1.5 or later once available to ensure the vulnerability is patched. 2) Until patches are applied, restrict access to the WebAccess/VPN interface to trusted networks and users only, minimizing exposure. 3) Implement strict input validation and output encoding on all user inputs, particularly in the NetworksController.addNetworkAction() function, to prevent injection of malicious scripts. 4) Deploy Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in browsers. 5) Monitor logs for suspicious activity related to network configuration changes or unusual user input patterns. 6) Conduct security awareness training to reduce the risk of social engineering that could facilitate user interaction required for exploitation. 7) Use web application firewalls (WAFs) with rules targeting XSS attack patterns to provide an additional layer of defense.
Description
Advantech WebAccess/VPN versions prior to 1.1.5 contain a stored cross-site scripting (XSS) vulnerability via NetworksController.addNetworkAction(). 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.