CVE-2026-4166 Wavlink WL-NU516U1 login.cgi sub_404F68 cross site scripting
Remote attackers can inject malicious scripts via the login page, potentially leading to session hijacking or code execution on Wavlink WL-NU516U1 routers.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-4166?
CVE-2026-4166 is a medium-severity cross-site scripting vulnerability in Wavlink WL-NU516U1, published on 15 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
A vulnerability was found in Wavlink WL-NU516U1 240425. The impacted element is the function sub_404F68 of the file /cgi-bin/login.cgi. The manipulation of the argument homepage/hostname results in cross site scripting. The attack can be launched remotely. The exploit has been made public and could be used. The vendor was contacted early about this disclosure.
Which versions are affected by CVE-2026-4166?
How do I fix CVE-2026-4166?
No fix has been published for CVE-2026-4166 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-4166 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4166 exists.
Sources
Also known as GHSA-xhc2-6qjv-5jpp.