CVE-2026-6559Public exploitNetwork attack vector

Browser script execution via unfiltered Hostname response

Published Apr 19, 2026 · Updated Apr 19, 2026

Cross-site scripting in Wavlink WL-WN579A3 firmware 220323 allows remote attackers to inject browser scripts through login.cgi. The sub_401F80 response builder inserts the Hostname request value into the generated login response without output encoding or filtering. Exploitation requires a user to load the crafted response, allowing attacker-controlled JavaScript to modify content in that browser session.

CVSS severity5.3
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Cross-site scripting in Wavlink WL-WN579A3 firmware 220323 allows remote attackers to inject browser scripts through login.cgi. The sub_401F80 response builder inserts the Hostname request value into the generated login response without output encoding or filtering. Exploitation requires a user to load the crafted response, allowing attacker-controlled JavaScript to modify content in that browser session.

The record

CVE
CVE-2026-6559
Published
Apr 19, 2026
Updated
Apr 19, 2026
Vendor
Wavlink
Product
WL-WN579A3
Classifications
CWE-79, CWE-94, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=220323

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Wavlink · WL-WN579A3version=220323

Published CVSS scores

4.3VulDBCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
5.0VulDBAV:N/AC:L/Au:N/C:N/I:P/A:N
5.3VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-94Improper Control of Generation of Code ('Code Injection')
T1059.007JavaScript/JScript

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo