Cyber Posture

CVE-2026-3661

MediumPublic PoC

Published: 07 March 2026

Published
07 March 2026
Modified
10 March 2026
KEV Added
Patch
CVSS Score 4.7 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L
EPSS Score 0.0023 46.0th percentile
Risk Priority 10 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-3661 is a medium-severity Injection (CWE-74) vulnerability in Wavlink Wl-Nu516U1 Firmware. Its CVSS base score is 4.7 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 46.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique.
Threat & Defense Details

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-74

Developer assessments and testing (including injection-focused techniques) identify improper neutralization of special elements, and the verifiable flaw remediation corrects them pre-deployment.

addresses: CWE-74

Identifies indicators of injection attacks (command, SQL, LDAP, etc.) via anomaly and attack monitoring.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
Why these techniques?

Command injection in exposed CGI endpoint (/cgi-bin/adm.cgi) directly enables remote arbitrary Unix command execution on the device firmware after valid admin authentication.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

A flaw has been found in Wavlink WL-NU516U1 240425. This affects the function ota_new_upgrade of the file /cgi-bin/adm.cgi. This manipulation of the argument model causes command injection. It is possible to initiate the attack remotely. The exploit has been published…

more

and may be used. The vendor was contacted early about this disclosure.

Deeper analysisAI

CVE-2026-3661 is a command injection vulnerability affecting the Wavlink WL-NU516U1 firmware version 240425. The flaw resides in the ota_new_upgrade function within the /cgi-bin/adm.cgi file, where manipulation of the model argument enables injection of arbitrary commands. It is remotely exploitable and classified under CWE-74 and CWE-77, with a CVSS v3.1 base score of 4.7 (AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L).

Attackers require high privileges, such as administrative access, to exploit this vulnerability over the network with low complexity and no user interaction. Successful exploitation grants limited impact, allowing low-level disclosure of information, modification of data, or denial of service.

References, including VulDB entries (ctiid.349550, id.349550, submit.758227) and a GitHub repository at jinhao118/cve/blob/main/WAVLINK_1.md, indicate that a public exploit is available for use. The vendor was contacted early about the disclosure, published on 2026-03-07.

Details

CWE(s)

Affected Products

wavlink
wl-nu516u1 firmware
m16u1_v240425

CVEs Like This One

CVE-2026-3662Same product: Wavlink Wl-Nu516U1
CVE-2026-3612Same product: Wavlink Wl-Nu516U1
CVE-2026-2615Same product: Wavlink Wl-Nu516U1
CVE-2025-10962Same product: Wavlink Wl-Nu516U1
CVE-2025-9149Same product: Wavlink Wl-Nu516U1
CVE-2026-3704Same product: Wavlink Wl-Nu516U1
CVE-2025-10964Same product: Wavlink Wl-Nu516U1
CVE-2025-10959Same product: Wavlink Wl-Nu516U1
CVE-2025-10958Same product: Wavlink Wl-Nu516U1
CVE-2025-10960Same product: Wavlink Wl-Nu516U1

References