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Memory Buffer Bounds ErrorWeakness · CWE-119

CVE-2026-7719

CRITICAL · 9.8 CVSS v3.1 Published 2026-05-04
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
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
A security flaw has been discovered in Totolink WA300 5.2cu.7112_B20190227. The affected element is the function loginauth of the file /cgi-bin/cstecgi.cgi of the component POST Request Handler. The manipulation of the argument http_host results in buffer overflow. The attack may be launched remotely. The exploit has been released to the public and may be used for attacks.

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

Buffer overflow vulnerability in the loginauth function of /cgi-bin/cstecgi.cgi on Totolink WA300 firmware 5.2cu.7112_B20190227. The http_host POST parameter is not properly bounds-checked, allowing an attacker to overflow a buffer and potentially execute arbitrary code remotely with the privileges of the web server.

MitigationUpdate to vendor-provided patched firmware if available; otherwise restrict network access to the cstecgi.cgi interface via firewall rules or disable the web management interface if not required for operation.

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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/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. Confirm device model is Totolink WA300
    Access the router's web interface or check the device label/marketing materials to verify the exact model number
    Affected if Device is not a Totolink WA300 model
  2. Identify installed firmware version
    Log into the router web UI and navigate to System Status or Firmware Upgrade page to view the current firmware version; alternatively, check via CLI if telnet/ssh is enabled
    Affected if Firmware version matches 5.2cu.7112_B20190227 or is an earlier version in the 5.2cu series
  3. Verify the CGI binary exists
    Send a crafted HTTP request to the device at the endpoint /cgi-bin/cstecgi.cgi (e.g., curl -X POST http://TARGET/cgi-bin/cstecgi.cgi) and observe the response
    Affected if The endpoint responds (indicating the CGI binary is present and the web interface is running)
  4. Check if remote administration is enabled
    In the router web UI, navigate to Administration or Remote Management settings to determine if remote access from WAN is permitted
    Affected if Remote administration/WAN access to the web interface is enabled

You are affected if you have a Totolink WA300 router running firmware version 5.2cu.7112_B20190227 or earlier, with the web interface accessible and remote administration enabled.

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 vendor-provided patched firmware if available; otherwise restrict network access to the cstecgi.cgi interface via firewall rules or disable the web management interface if not required for operation.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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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-2026-7719 in production — separate from our analysis above.

No notes yet

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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