CVE-2026-13539Public exploitNetwork attack vector

Authenticated device compromise via Guest_ssid stack overflow

Published Jun 29, 2026 · Updated Jun 29, 2026

Stack-based buffer overflow in Wavlink WL-NU516U1-A M16U1_V240425 allows remote authenticated users to corrupt process memory. The sub_407504 routine in /cgi-bin/wireless.cgi uses unbounded sprintf to place Guest_ssid data into a 1,028-byte stack buffer, overwriting the return address. Low-privileged web access is required; a crafted POST request can crash the handler or redirect control flow for device compromise.

CVSS severity8.8
High
EPSS probability0.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Wavlink WL-NU516U1-A M16U1_V240425 allows remote authenticated users to corrupt process memory. The sub_407504 routine in /cgi-bin/wireless.cgi uses unbounded sprintf to place Guest_ssid data into a 1,028-byte stack buffer, overwriting the return address. Low-privileged web access is required; a crafted POST request can crash the handler or redirect control flow for device compromise.

The record

CVE
CVE-2026-13539
Published
Jun 29, 2026
Updated
Jun 29, 2026
Vendor
Wavlink
Product
WL-NU516U1-A
Classifications
CWE-119, CWE-121, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 29, 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.

  1. Affected versionversion=M16U1_V240425

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Wavlink · WL-NU516U1-Aversion=M16U1_V240425

Published CVSS scores

7.4VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
9.0VulDBAV:N/AC:L/Au:S/C:C/I:C/A:C
8.8VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-121Stack-based Buffer Overflow
T1190Exploit Public-Facing Application

Public exploit references

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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