dbcve.org
InjectionWeakness · CWE-74

CVE-2026-2548

MEDIUM · 6.3 CVSS v3.1 Published 2026-02-16
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
69/100
Remediation priority · Elevated
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 flaw has been found in WAYOS FBM-220G 24.10.19. This affects the function sub_40F820 of the file rc. Executing a manipulation of the argument upnp_waniface/upnp_ssdp_interval/upnp_max_age can lead to command injection. The attack can be executed remotely. The vendor was contacted early about this disclosure but did not respond in any way.

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

Command injection vulnerability in WAYOS FBM-220G router firmware (version 24.10.19) in the rc file's sub_40F820 function. Remote attackers can inject arbitrary commands via the upnp_waniface, upnp_ssdp_interval, or upnp_max_age parameters due to insufficient input sanitization before use in system calls.

MitigationImplement strict input validation and sanitization on the affected UPnP parameters before they are used in system commands. If available, apply vendor firmware updates; otherwise, consider compensating controls such as network segmentation to limit exposure.

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
Low
Integrity
Low
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

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 administration interface or CLI and confirm the device is a WAYOS FBM-220G model. This can typically be found on the status page or via the 'system' or 'device info' command in the firmware CLI.
    Affected if The device is not a WAYOS FBM-220G, the vulnerability does not apply.
  2. Check firmware version
    Navigate to the router's web interface status page, or use the CLI command to display firmware version (commonly 'version' or 'show version' depending on the WAYOS firmware interface). Compare the displayed version against 24.10.19.
    Affected if The installed firmware version is 24.10.19 - only this specific version is listed as affected in the CVE summary.
  3. Verify UPnP configuration access
    Locate the UPnP settings in the router web interface, typically under 'Advanced' > 'UPnP' or 'NAT' settings. Confirm whether the UPnP service is enabled or accessible.
    Affected if UPnP is disabled and not accessible, the attack surface is reduced though the vulnerable code may still be present in the firmware.
  4. Inspect vulnerable parameters
    If UPnP is accessible, examine the configuration options for parameters named upnp_waniface, upnp_ssdp_interval, or upnp_max_age. These fields accept values that are passed to the vulnerable sub_40F820 function in the rc startup file without sanitization.
    Affected if These specific UPnP parameters exist and accept user-supplied input - that input could be leveraged for command injection.

You are affected if you have a WAYOS FBM-220G router running firmware version 24.10.19 with accessible UPnP configuration that includes the upnp_waniface, upnp_ssdp_interval, or upnp_max_age parameters.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement strict input validation and sanitization on the affected UPnP parameters before they are used in system commands. If available, apply vendor firmware updates; otherwise, consider compensating controls such as network segmentation to limit exposure.

Recommended fix Low confidence
  1. Isolate the WAYOS FBM-220G device on a restricted network segment with firewall rules limiting access to only trusted IP addresses
  2. If the device's web interface or API is exposed, disable remote access and limit management to local network only
  3. Implement input validation and filtering at upstream network devices (firewall/WAF) for requests targeting the vulnerable parameters (upnp_waniface, upnp_ssdp_interval, upnp_max_age)
  4. Monitor network traffic for suspicious patterns related to UPnP configuration endpoints
  5. If possible, disable the UPnP functionality entirely on the device if it is not required for operations
  6. Contact the vendor (WAYOS) through alternate channels to request security patch for CVE-2026-2548

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA3.0 h
27.0 hours of engineering $4,800
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,680.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-2548 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2026-2548 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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