Memory Buffer Bounds ErrorWeakness · CWE-119

CVE-2026-9389

HIGH · 8.8 CVSS v3.1 Published 2026-05-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable 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
A security vulnerability has been detected in Tenda F456 1.0.0.5. This affects the function frmL7ImForm of the file /goform/L7Im. The manipulation of the argument page leads to buffer overflow. The attack can be initiated remotely. The exploit has been disclosed publicly and may be used.

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

Buffer overflow vulnerability in Tenda F456 router firmware 1.0.0.5 in the /goform/L7Im endpoint. The frmL7ImForm function does not properly validate the 'page' parameter before use, allowing remote attackers to overflow a buffer and potentially execute arbitrary code.

MitigationRestrict remote access to the router's web management interface, check Tenda for firmware updates, and if no patch is available, consider replacing the device with a currently supported model.

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 checks

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

  1. Identify the router model
    Log into the router web interface or check the device label to confirm it is a Tenda F456 model
    Affected if The device is not a Tenda F456 router, then it is not affected by this specific CVE
  2. Check the firmware version
    Access the router admin panel, typically at 192.168.0.1, and navigate to System Status or Firmware Upgrade page to view the installed firmware version
    Affected if The firmware version is 1.0.0.5, indicating it matches the affected version
  3. Verify the web management interface is accessible
    Attempt to access the router login page at http://192.168.0.1 or the configured LAN IP address using a web browser
    Affected if The web interface is accessible from the network, meaning the attack surface exists for the vulnerable handler
  4. Confirm the L7Im handler exists
    Send an HTTP GET or POST request to the /goform/L7Im endpoint, such as: curl -s http://192.168.0.1/goform/L7Im or inspect the router's web binary for the frmL7ImForm function
    Affected if The /goform/L7Im endpoint responds or the function is present in the firmware binary, confirming the vulnerable component is present
  5. Test the page parameter for length validation
    Send a crafted HTTP request to /goform/L7Im with an unusually long string in the 'page' parameter, for example: curl -X POST -d 'page=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA...' http://192.168.0.1/goform/L7Im and observe if the router crashes, reboots, or accepts arbitrary-length input without rejecting it
    Affected if The router accepts an excessively long page parameter without proper bounds checking, indicating the buffer overflow vulnerability is present and exploitable

If the device is a Tenda F456 running firmware 1.0.0.5 and the /goform/L7Im web handler is accessible, then the environment is affected by CVE-2026-9389.

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

Restrict remote access to the router's web management interface, check Tenda for firmware updates, and if no patch is available, consider replacing the device with a currently supported model.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2026-9389 in production — separate from our analysis above.

No notes yet

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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
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  • Version or environment caveats, and links to real fixes
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