Stack-based Buffer OverflowWeakness · CWE-121

CVE-2026-36822

HIGH · 7.5 CVSS v3.1 Published 2026-06-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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
Shenzhen Tenda Technology Co., Ltd Tenda W20E v15.11.0.6 was discovered to contain a buffer overflow in the macAddr parameter of the formDelStaState 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 confidence

A buffer overflow vulnerability exists in the macAddr parameter of the formDelStaState function in Tenda W20E router firmware v15.11.0.6. An unauthenticated remote attacker can send a crafted HTTP request with an oversized macAddr value to overflow the buffer, causing the device to crash and resulting in a Denial of Service.

MitigationApply any vendor-supplied firmware update for the Tenda W20E. If no update is available, restrict network access to the router's management interface using firewall rules or VLAN segmentation to prevent unauthorized HTTP requests.

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 checks

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

  1. Identify device model
    Access the router web interface or check the device label to confirm the model is Tenda W20E
    Affected if Device model is Tenda W20E
  2. Check firmware version
    Log into the router admin panel and navigate to System Settings or Status page to view the firmware version; compare against v15.11.0.6
    Affected if Firmware version is 15.11.0.6 or falls within the affected version range
  3. Verify HTTP management interface accessibility
    Check router firewall settings to determine if the web management interface (HTTP/HTTPS ports) is accessible from external networks or untrusted IPs
    Affected if Remote HTTP management is enabled and exposed to untrusted networks
  4. Inspect for crash logs or device instability
    Review system logs or uptime status for unexplained reboots, crash dumps, or frequent device resets occurring without user intervention
    Affected if Device exhibits unexpected crashes or reboots that correlate with external HTTP requests
  5. Review HTTP request logging
    Check router access logs for unusually long macAddr parameter values in formDelStaState POST requests originating from external sources
    Affected if Logs show long macAddr values in formDelStaState requests from untrusted IPs

The device is affected if it is a Tenda W20E running firmware v15.11.0.6 (or affected version) with its HTTP management interface exposed to untrusted networks.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply any vendor-supplied firmware update for the Tenda W20E. If no update is available, restrict network access to the router's management interface using firewall rules or VLAN segmentation to prevent unauthorized HTTP requests.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,060
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Scan for this in your stack

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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-2026-36822 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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