CVE-2026-3613
Published: 06 March 2026
Summary
CVE-2026-3613 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Wavlink Wl-Nu516U1 Firmware. Its CVSS base score is 7.3 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 34.7th 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 SI-16 (Memory Protection).
Deeper analysis
CVE-2026-3613 is a stack-based buffer overflow vulnerability in the Wavlink WL-NU516U1 router firmware version V240425. The flaw affects the sub_401A0C function within the /cgi-bin/login.cgi component, triggered by manipulation of the ipaddr argument. Associated with CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-121 (Stack-based Buffer Overflow), it was published on 2026-03-06 with a CVSS v3.1 base score of 7.2 (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H).
The vulnerability enables remote exploitation by an attacker possessing high privileges on the target system. Successful exploitation can result in high-impact compromise of confidentiality, integrity, and availability, potentially allowing arbitrary code execution or system crashes. A public exploit is available, as detailed in a GitHub repository, which may facilitate attacks against vulnerable devices.
Advisories from VulDB (ctiid.349221, id.349221, submit.755341) and the referenced GitHub proof-of-concept confirm the remote attack vector and public disclosure of the exploit. The vendor was contacted early regarding the issue, though no specific patches or mitigations are outlined in these sources. Security practitioners should monitor for firmware updates and restrict access to the affected login.cgi endpoint.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-9965
Vulnerability details
A vulnerability was identified in Wavlink WL-NU516U1 V240425. This vulnerability affects the function sub_401A0C of the file /cgi-bin/login.cgi. Such manipulation of the argument ipaddr leads to stack-based buffer overflow. It is possible to launch the attack remotely. The exploit is…
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publicly available and might be used. The vendor was contacted early about this disclosure.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Stack-based buffer overflow in public-facing /cgi-bin/login.cgi web endpoint of router firmware directly enables remote authenticated RCE via exploitation of an Internet-facing application (T1190).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly enforces validation of the ipaddr argument in login.cgi to block the oversized input that triggers the stack buffer overflow.
Applies memory-protection mechanisms that can stop stack-based buffer overflows from achieving arbitrary code execution on the router firmware.
Limits the high-privilege accounts required for exploitation, reducing the number of accounts that can reach the vulnerable sub_401A0C function.