CVE-2026-34804: Endian Firewall stored XSS in QoS rules dscp parameter

CVE-2026-34804 · 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 in its Quality of Service (QoS) management interface. An authorized user can inject malicious scripts into the system's configuration rules. When other administrators view these rules, the scripts execute automatically, potentially allowing the attacker to hijack administrative sessions or perform unauthorized actions on the firewall.

Technologies: Endian Firewall Community. Vendors: Endian.

Quick answers

Is CVE-2026-34804 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-34804 being exploited in the wild.
How severe is CVE-2026-34804?
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-2026-34804?
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-2026-34804 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-34804?
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 vulnerability is located in the '/manage/qos/rules/' endpoint and is triggered by improper neutralization of the 'dscp' parameter. An authenticated attacker with network access to the management interface can submit a crafted request containing malicious JavaScript. This script is stored on the server and executed in the context of any user (typically an administrator) who subsequently navigates to the affected Quality of Service rules page. This can lead to session hijacking, unauthorized configuration changes, or further exploitation of the administrative interface.

Affected products

  • Endian Firewall Community <= 3.3.25

Timeline

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

References

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