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Memory Buffer Bounds ErrorWeakness · CWE-119

CVE-2026-6199

HIGH · 8.8 CVSS v3.1 Published 2026-04-13
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 vulnerability was found in Tenda F456 1.0.0.5. Impacted is the function fromqossetting of the file /goform/qossetting. The manipulation of the argument page results in stack-based buffer overflow. It is possible to launch the attack remotely. The exploit has been made public and could 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 · high confidence

Stack-based buffer overflow in Tenda F456 router firmware 1.0.0.5 in the /goform/qossetting endpoint. The fromqossetting function fails to properly bounds-check the 'page' argument before copying it to a stack-allocated buffer, allowing remote attackers to overwrite return addresses and achieve arbitrary code execution.

MitigationUpdate to patched firmware if available; otherwise, block external access to the /goform/qossetting endpoint at the network perimeter or disable qos functionality if the device supports it.

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 device model
    Access the router admin interface or check the device label to confirm the model is Tenda F456
    Affected if Device is a Tenda F456 router
  2. Check firmware version
    Navigate to router admin panel (typically 192.168.0.1) and look in System Settings or Administration > Firmware Upgrade to find the installed version number
    Affected if Firmware version is 1.0.0.5 or earlier on the Tenda F456
  3. Verify qossetting endpoint accessibility
    Attempt to access the URI /goform/qossetting via HTTP from an internal network host (e.g., curl http://192.168.0.1/goform/qossetting)
    Affected if The endpoint responds with any HTTP status (indicating it is exposed and reachable)
  4. Check if QoS is enabled
    In router admin panel, navigate to QoS or Bandwidth Control settings and determine if QoS functionality is turned on
    Affected if QoS feature is enabled on the device

A user is affected if they have a Tenda F456 router running firmware 1.0.0.5 (or earlier) with the QoS feature enabled and the /goform/qossetting endpoint accessible on the network.

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

Update to patched firmware if available; otherwise, block external access to the /goform/qossetting endpoint at the network perimeter or disable qos functionality if the device supports it.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,440
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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-2026-6199 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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