# CVE-2026-34809: Endian Firewall stored XSS in zonefw.cgi remark parameter

Source: https://junglewise.ai/threats/cve-2026-34809-endian-firewall-stored-xss-in-zonefw-cgi-remark-parameter  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-02. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2026-34809 · Severity: medium · CVSS 6.4 · Published 2026-04-02

Endian Firewall, a security appliance used to protect and manage network traffic, contains a vulnerability that allows an attacker to inject malicious scripts into the management interface. An authorized user could save a specially crafted comment that, when viewed by another administrator, executes hidden code in their browser. This could lead to unauthorized actions being performed on behalf of other administrators or the theft of sensitive session information.

Technologies: [Endian Firewall Community](https://junglewise.ai/threats/technologies/firewall-community). Vendors: [Endian](https://junglewise.ai/threats/vendors/endian).

## Quick answers

**Is CVE-2026-34809 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-34809 being exploited in the wild.

**How severe is CVE-2026-34809?** Medium severity, with a CVSS score of 6.4, published 2 April 2026.

**Which products and versions are affected?** Endian Firewall Community up to and including 3.3.25.

**Is there a fix for CVE-2026-34809?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-34809 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-34809?** Check whether you run Endian Firewall Community at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A stored cross-site scripting (XSS) vulnerability exists in Endian Firewall version 3.3.25 and earlier. The flaw is located in the '/cgi-bin/zonefw.cgi' component, specifically within the 'remark' parameter, which fails to properly neutralize user-supplied input before it is stored and rendered in the web interface. An authenticated attacker with network access to the management console can submit a malicious script that will execute in the context of any user who subsequently views the firewall zone configuration page. This can result in session hijacking or unauthorized configuration changes. Users are advised to check for updates in the Endian Community release notes.

## Affected products

- Endian Firewall Community up to and including 3.3.25

## Timeline

- 2026-04-02: disclosed
- 2026-04-02: advisory

## References

- [https://help.endian.com/hc/en-us/sections/360004371358-Community](https://help.endian.com/hc/en-us/sections/360004371358-Community)
- [https://www.vulncheck.com/advisories/endian-firewall-cgi-bin-zonefw-cgi-remark-stored-cross-site-scripting](https://www.vulncheck.com/advisories/endian-firewall-cgi-bin-zonefw-cgi-remark-stored-cross-site-scripting)

## Related threats

- [Endian Firewall stored XSS in remark parameter](https://junglewise.ai/threats/cve-2026-34823-endian-firewall-stored-xss-in-remark-parameter)
- [Endian Firewall stored XSS in certificate management interface](https://junglewise.ai/threats/cve-2026-34822-endian-firewall-stored-xss-in-certificate-management-interface)
- [Endian Firewall stored XSS in VPN user remark parameter](https://junglewise.ai/threats/cve-2026-34821-endian-firewall-stored-xss-in-vpn-user-remark-parameter)
- [Endian Firewall stored XSS in IPsec remark parameter](https://junglewise.ai/threats/cve-2026-34820-endian-firewall-stored-xss-in-ipsec-remark-parameter)
- [Endian Firewall stored XSS in openvpnclient.cgi](https://junglewise.ai/threats/cve-2026-34819-endian-firewall-stored-xss-in-openvpnclient-cgi)