# CVE-2026-34818: Endian Firewall stored XSS in dnsmasq local domains remark parameter

Source: https://junglewise.ai/threats/cve-2026-34818-endian-firewall-stored-xss-in-dnsmasq-local-domains-remark  
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-2026-34818 · Severity: medium · CVSS 6.4 · Published 2026-04-02

Endian Firewall, a security appliance used to protect network perimeters, is vulnerable to a security flaw where malicious scripts can be saved within the system's configuration pages. An attacker with basic login credentials can inject these scripts into the 'remark' field of the local domains management section. When an administrator later views that page, the script executes in their browser, potentially allowing the attacker to perform unauthorized actions or steal 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-2026-34818 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-34818 being exploited in the wild.

**How severe is CVE-2026-34818?** 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-2026-34818?** 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-2026-34818 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-34818?** 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 versions up to and including 3.3.25. The vulnerability is located in the '/manage/dnsmasq/localdomains/' endpoint, specifically within the 'remark' parameter, which fails to properly neutralize user-supplied input. An authenticated attacker with low privileges can submit a malicious payload that is permanently stored on the server. When a victim (typically an administrator) accesses the local domains management page, the payload executes in the context of their session. This can lead to session hijacking, unauthorized configuration changes, or further escalation of privileges within the web management interface.

## Affected products

- Endian Firewall Community <= 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-manage-dnsmasq-localdomains-remark-stored-cross-site-scripting](https://www.vulncheck.com/advisories/endian-firewall-manage-dnsmasq-localdomains-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)