OS Command InjectionWeakness · CWE-78

CVE-2026-41923

CRITICAL · 9.3 CVSS v4.0 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
WDR201A WiFi Extender (HW V2.1, FW LFMZX28040922V1.02) contains an OS command injection vulnerability in the internet.cgi binary that allows unauthenticated remote attackers to execute arbitrary shell commands by injecting malicious input into the gateway POST parameter. Attackers can exploit unsanitized parameter concatenation in the set_add_routing function to inject shell commands that are executed via popen() with partial output reflected in the HTTP response.

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

OS command injection vulnerability in WDR201A WiFi Extender (FW V1.02) internet.cgi binary. Unauthenticated attackers can inject arbitrary shell commands via the gateway POST parameter in the set_add_routing function, which concatenates unsanitized input directly into a popen() call.

MitigationApply vendor firmware patch if available; otherwise restrict device management interface to trusted networks or disable remote administration to reduce attack surface until patch is obtainable.

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
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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
    Check the device label or admin interface for the exact model number WDR201A
    Affected if Device is not the WDR201A WiFi Extender, then it is not affected by this specific CVE
  2. Check firmware version
    Access the device admin interface (typically via web browser at 192.168.0.1 or 192.168.1.1) and navigate to Status or System settings to view the firmware version
    Affected if Firmware version is V1.02 and no patch has been applied, the device is running the vulnerable version
  3. Verify internet.cgi exists
    Access the device web interface and attempt to locate or access the internet.cgi binary via the URL path (commonly at /cgi-bin/internet.cgi or similar)
    Affected if The internet.cgi binary is present and accessible on the device, the attack surface exists
  4. Check if remote management is enabled
    In the device admin interface, locate the Remote Management or Remote Access settings (often under Administration or Advanced settings)
    Affected if Remote management or remote administration is enabled and the device is exposed to untrusted networks, the vulnerability is remotely exploitable
  5. Confirm set_add_routing function is present
    Inspect the internet.cgi binary or its configuration files for the set_add_routing function handler
    Affected if The set_add_routing function exists in the CGI binary, the specific vulnerable code path is present

The device is affected if it is a WDR201A WiFi Extender running firmware V1.02 with the internet.cgi binary accessible and remote management enabled, allowing unauthenticated attackers to inject commands via the gateway POST parameter.

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 vendor firmware patch if available; otherwise restrict device management interface to trusted networks or disable remote administration to reduce attack surface until patch is obtainable.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
32.0 hours of engineering $5,600
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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-2026-41923 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
  • 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