CVE-2026-3661
Published: 07 March 2026
Summary
CVE-2026-3661 is a medium-severity Injection (CWE-74) vulnerability in Wavlink Wl-Nu516U1 Firmware. Its CVSS base score is 5.1 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 47.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and AC-6 (Least Privilege).
Deeper analysis
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.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-10141
Vulnerability details
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…
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and may be used. The vendor was contacted early about this disclosure.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
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.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly mitigates the command injection by enforcing validation and sanitization of the model argument passed to ota_new_upgrade in adm.cgi.
Limits the number of accounts with the high privileges required to reach and exploit the vulnerable CGI function.
Restricts unnecessary firmware functions or CGI endpoints, reducing exposure of the ota_new_upgrade code path.