Reflected XSS via unencoded login parameters
Published Mar 15, 2026 · Updated Mar 15, 2026
Reflected XSS in Wavlink WL-NU516U1 240425 allows remote authenticated users to execute script in a user's browser via a crafted login request. The login.cgi path for page=login passes homepage or hostname through sprintf into a response buffer, and sub_404F68 returns the values without output encoding. Valid device credentials and user interaction with the crafted response are required; execution is confined to the browser context of the management interface.
Summary
What happened
Reflected XSS in Wavlink WL-NU516U1 240425 allows remote authenticated users to execute script in a user's browser via a crafted login request. The login.cgi path for page=login passes homepage or hostname through sprintf into a response buffer, and sub_404F68 returns the values without output encoding. Valid device credentials and user interaction with the crafted response are required; execution is confined to the browser context of the management interface.
The record
- CVE
- CVE-2026-4166
- Published
- Mar 15, 2026
- Updated
- Mar 15, 2026
- Vendor
- Wavlink
- Product
- WL-NU516U1
- Classifications
- CWE-79, CWE-94, T1059.007
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 15, 2026CVE publishedPublication date reported by the CVE source.
- Mar 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=240425
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- WL-NU516U1 homepage reflected-XSS PoCproof of concept · demonstrated
- WL-NU516U1 hostname reflected-XSS PoCproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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