CVE-2026-13563
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 · uneditedA vulnerability has been found in Edimax EW-7478APC 1.04. This impacts the function formL2TPSetup of the file /goform/formL2TPSetup of the component POST Request Handler. Such manipulation of the argument L2TPUserName leads to stack-based buffer overflow. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
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 confidenceStack-based buffer overflow in Edimax EW-7478APC 1.04's L2TP VPN setup form (/goform/formL2TPSetup) where the L2TPUserName POST parameter is not properly bounds-checked before being copied to a stack buffer, allowing remote attackers to overwrite return addresses and potentially achieve arbitrary code execution.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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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Identify the device modelAccess the router's web interface or check the device label to confirm the model is Edimax EW-7478APCAffected if The device is not an Edimax EW-7478APC, then it is not affected by this specific CVE
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Check the firmware versionNavigate to the router's web management interface, typically at 192.168.1.1, and locate the firmware version in the System or Status section. Compare the version to 1.04Affected if The firmware version is exactly 1.04, then it is within the affected range
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Verify L2TP functionality is accessibleAttempt to access the L2TP setup page by navigating to /goform/formL2TPSetup or locate the L2TP configuration section in the router's web interface under VPN or Network settingsAffected if The L2TP setup page exists and is accessible, indicating the vulnerable function is present
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Check if web management interface is exposedDetermine if the router's web interface is accessible from the WAN/internet by attempting to access the router's public IP on port 80/443, or review port forwarding/NAT rulesAffected if The web management interface is exposed to untrusted networks, the vulnerability could be exploited remotely
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Confirm the L2TP parameter handlingReview HTTP POST requests to /goform/formL2TPSetup and observe if the L2TPUserName parameter is accepted without length validation when submitting L2TP configurationAffected if The L2TPUserName field accepts arbitrarily long input without error, the vulnerable code path is present
A user is affected if they have an Edimax EW-7478APC router running firmware version 1.04 with the L2TP feature accessible through the web management interface.
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 dataIsolate the device from untrusted networks or disable L2TP functionality entirely; if L2TP is required and device cannot be replaced, implement strict access controls to limit POST requests to the form to trusted sources only.
- Consultation4.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-13563 — 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-2026-13563 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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- Version or environment caveats, and links to real fixes
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