CVE-2026-36823
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 · uneditedShenzhen Tenda Technology Co., Ltd Tenda W20E v15.11.0.6 was discovered to contain a buffer overflow in the webAuthUserInfo parameter of the formAddWebAuthUser function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted HTTP request.
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 · moderate confidenceA buffer overflow vulnerability exists in the formAddWebAuthUser function of Tenda W20E router firmware v15.11.0.6. The webAuthUserInfo parameter in HTTP requests is not properly bounds-checked, allowing attackers to send oversized input that overflows the buffer and causes the device to crash (Denial of Service).
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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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.
-
Confirm Tenda W20E modelAccess router web interface or check device label/marketing to verify the model number is W20EAffected if Device is not a Tenda W20E router
-
Check firmware versionLog into the router web interface and navigate to System Status or Firmware Upgrade page to view the installed firmware version, or use 'telnet' or 'ssh' to access the device and run 'cat /proc/version' or 'cat /etc/version' if availableAffected if Firmware version is 15.11.0.6 exactly
-
Verify web management interface is enabledAttempt to access the router login page at http://[router-ip] or https://[router-ip] using a browserAffected if Web interface returns a connection timeout or error, indicating it is disabled or blocked
-
Check if web authentication feature is configuredLog into the router web interface and look for Web Authentication, Access Control, or User Management settings under the relevant configuration menuAffected if Web authentication feature is not present or not configured in the system
A user is affected if they are running Tenda W20E router with firmware version 15.11.0.6, have the web management interface enabled, and the web authentication feature is accessible.
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 dataApply the vendor firmware patch when available. Until then, block external access to the router's web management interface using firewall rules or disable remote web administration to prevent unauthenticated attackers from reaching the vulnerable formAddWebAuthUser endpoint.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-36823 — 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-2026-36823 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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.
- 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