# CVE-2026-34807: Endian Firewall stored XSS in incoming.cgi remark parameter

Source: https://junglewise.ai/threats/cve-2026-34807-endian-firewall-stored-xss-in-incoming-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-2026-34807 · Severity: medium · CVSS 6.4 · Published 2026-04-02

Endian Firewall, a security appliance used to protect network perimeters, contains a vulnerability that allows malicious code to be saved on its management interface. An attacker with basic login credentials can inject scripts that will run in the browsers of other administrators when they view specific configuration pages. This could lead to the theft of session cookies or unauthorized configuration changes by hijacking an administrator's session.

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

## Quick answers

**Is CVE-2026-34807 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-34807 being exploited in the wild.

**How severe is CVE-2026-34807?** Medium severity, with a CVSS score of 6.4, published 2 April 2026.

**Which products and versions are affected?** Endian Firewall Community <= 3.3.25.

**Is there a fix for CVE-2026-34807?** 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-2026-34807 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-34807?** 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/incoming.cgi' component, which fails to properly neutralize user-supplied input in the 'remark' parameter. An authenticated attacker with low privileges can submit a malicious script that is permanently stored on the server. When an administrative user subsequently accesses the affected page, the script executes within their browser context. This can be leveraged to perform actions on behalf of the administrator or exfiltrate sensitive session information.

## Affected products

- Endian Firewall Community <= 3.3.25

## Timeline

- 2026-04-02: disclosed: Initial disclosure by VulnCheck
- 2026-04-02: advisory: NVD published the CVE entry

## 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-incoming-cgi-remark-stored-cross-site-scripting](https://www.vulncheck.com/advisories/endian-firewall-cgi-bin-incoming-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)