CVE-2026-34807
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 · uneditedEndian Firewall version 3.3.25 and prior allow stored cross-site scripting (XSS) via the remark parameter to /cgi-bin/incoming.cgi. 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 confidenceEndian Firewall 3.3.25 and prior contains a stored XSS vulnerability in the /cgi-bin/incoming.cgi CGI script via the 'remark' parameter. An authenticated attacker can inject arbitrary JavaScript that persists in the application and executes in the browsers of other users who view the affected page.
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<= 3.3.25CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Confirm Endian Firewall installation and versionCheck the installed Endian Firewall version. On the management interface, navigate to System > Status or check /etc/redhat-release or /etc/ endian-version if accessible via SSH. Alternatively, inspect HTTP response headers from the web interface for version information.Affected if The installed version is 3.3.25 or any prior version (anything <= 3.3.25).
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Verify the vulnerable endpoint existsConfirm the web server responds to /cgi-bin/incoming.cgi. This can be done by accessing the URL directly in a browser or using curl: curl -k https://<your-firewall-ip>/cgi-bin/incoming.cgiAffected if The endpoint returns a valid HTTP response (200 or 403), indicating it is accessible and potentially in use.
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Identify if incoming mail/ fax relay functionality is enabledThe incoming.cgi typically handles incoming mail or fax relay features. Check the Endian Firewall web interface under Mail > Incoming or similar sections where users can add remarks or notes to incoming connections.Affected if The incoming mail or fax relay feature with remark/note capability is enabled and accessible to authenticated users.
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Inspect stored data in the remark parameterIf you have database access, query the SQL database (typically MySQL/PostgreSQL on Endian) for records containing the 'remark' field in tables related to incoming mail/fax. Alternatively, log into the web interface and navigate to pages displaying incoming records to visually inspect for suspicious script tags in remark fields.Affected if The database or web interface displays unsanitized HTML or JavaScript characters (<script>, javascript:, onerror=, etc.) within remark fields, confirming active exploitation.
A user is affected if they run Endian Firewall Community version 3.3.25 or earlier AND the incoming mail/fax relay feature with the remark parameter is accessible to authenticated users on their network.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor dataImplement proper input validation and output encoding for the remark parameter in incoming.cgi, or apply vendor patch if available. Consider implementing Content Security Policy headers as defense-in-depth.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-34807 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-34807 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data