CVE-2026-4166: Wavlink WL-NU516U1 login.cgi sub_404F68 cross site scripting

Vulnerability summary

CVE-2026-4166 is a medium (CVSS 5.1) Cross-site Scripting vulnerability in wavlink wl-nu516u1_firmware. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 28.7% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 15-03-2026
   PublishedVulnerability first disclosed.
2. 17-03-2026
   Last modifiedVulnerability information updated.

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.

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
• CWE-94Improper Control of Generation of Code ('Code Injection')The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.