CVE-2026-2565 Wavlink WL-NU516U1 adm.cgi sub_40785C stack-based overflow

High 7.5 Published 16 Feb 2026 Updated 23 Feb 2026

Remote attackers can trigger a stack-based buffer overflow in the Wavlink WL-NU516U1 router's admin interface, potentially leading to code execution.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-2565?

CVE-2026-2565 is a high-severity memory corruption vulnerability in Wavlink WL-NU516U1, published on 16 Feb 2026. An attacker needs administrator access to exploit it, with no action from the victim.

Official description

A weakness has been identified in Wavlink WL-NU516U1 20251208. Affected by this issue is the function sub_40785C of the file /cgi-bin/adm.cgi. This manipulation of the argument time_zone causes stack-based buffer overflow. The attack can be initiated remotely. The attack is considered to have high complexity. The exploitation is known to be difficult. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-121, CWE-119

Which versions are affected by CVE-2026-2565?

It affects 1 product.

Products include Wavlink Wl-Nu516u1 Firmware.

How do I fix CVE-2026-2565?

No fix has been published for CVE-2026-2565 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-2565 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-2565 exists.

Sources

Also known as GHSA-3jhg-wm5r-8rfq.