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Firewall CommunityApplication · Endian

CVE-2026-34804

MEDIUM · 5.4 CVSS v3.1 Published 2026-04-02
Fix available
A fix is available. Upgrade to after 3.3.25 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Endian Firewall version 3.3.25 and prior allow stored cross-site scripting (XSS) via the dscp parameter to /manage/qos/rules/. An authenticated attacker can inject arbitrary JavaScript that is stored and executed when other users view the affected page.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Stored XSS vulnerability in Endian Firewall's QoS rules management interface (version 3.3.25 and prior). An authenticated attacker can inject malicious JavaScript through the dscp parameter at /manage/qos/rules/, which persists and executes when other users view the affected page.

MitigationUpgrade Endian Firewall to a version newer than 3.3.25, or implement strict input validation and output encoding on the dscp parameter to prevent XSS injection.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Firewall CommunityApplication
Affected:<= 3.3.25

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Endian Firewall installation and version
    Locate the Endian Firewall installation and determine its exact version number (typically visible in the system dashboard, about page, or via the command line interface if accessible).
    Affected if The installed version is Endian Firewall Community 3.3.25 or any prior version.
  2. Confirm QoS module is enabled
    Access the Endian Firewall admin interface and verify whether the QoS (Quality of Service) module or feature is currently enabled in the system configuration.
    Affected if The QoS module is enabled and functional in the firewall.
  3. Access QoS rules management interface
    Navigate to the QoS rules management page at /manage/qos/rules/ using the web admin interface and log in with valid credentials.
    Affected if You can successfully access the QoS rules management interface with an authenticated session.
  4. Inspect existing QoS rules for suspicious content
    Review all QoS rules listed in the management interface and examine the dscp parameter values for any unexpected, encoded, or suspicious-looking strings that may indicate injected JavaScript code.
    Affected if Any QoS rule contains unsanitized or malformed dscp values that could contain XSS payloads.

A user is affected if they are running Endian Firewall Community version 3.3.25 or earlier, have the QoS module enabled, and have QoS rules with potentially malicious dscp parameter values present in the system.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 3.3.25
Interim mitigation

Upgrade Endian Firewall to a version newer than 3.3.25, or implement strict input validation and output encoding on the dscp parameter to prevent XSS injection.

Recommended fix Moderate confidence

Endian Firewall Community 3.3.26 or later

  1. 1. Check current Endian Firewall Community version via the web interface (System > Status) or command line (grep version /etc/*release* or similar)
  2. 2. Navigate to the QoS rules section at /manage/qos/rules/ to confirm the vulnerable endpoint exists in your installation
  3. 3. If version is 3.3.25 or lower, plan for upgrade to version 3.3.26 or later which contains the fix for CVE-2026-34804
  4. 4. Before upgrading, backup current configuration via the web interface (Maintenance > Backup) or /var/tmp/backup directory
  5. 5. Perform the upgrade following Endian's standard upgrade procedure for Community edition
  6. 6. After upgrade, verify the new version is running and navigate to /manage/qos/rules/ to confirm the page loads correctly
  7. 7. Validate the fix by attempting to inject benign test payload in the dscp parameter (e.g., <script>alert('test')</script>) and confirming it is properly sanitized/escaped
Caveat Minor: Review QoS rule configurations after upgrade as template changes may occur between minor versions

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Firewall Community Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-34804 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data