CVE-2026-3613Public exploitNetwork attack vector

Authenticated CGI crash via unbounded sprintf

Published Mar 6, 2026 · Updated Mar 6, 2026

Stack buffer overflow in Wavlink WL-NU516U1 V240425 allows remote authenticated users to crash login.cgi via a crafted ipaddr value. In sub_401A0C, sprintf inserts the unbounded ipaddr value into a 128-byte stack buffer, overwriting the stack frame and return address. Exploitation requires an administrator-password hash and valid session cookie; the demonstrated consequence is a login.cgi segmentation fault and HTTP 500 response.

CVSS severityUnavailable
Unscored
EPSS probability0.71%
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

Stack buffer overflow in Wavlink WL-NU516U1 V240425 allows remote authenticated users to crash login.cgi via a crafted ipaddr value. In sub_401A0C, sprintf inserts the unbounded ipaddr value into a 128-byte stack buffer, overwriting the stack frame and return address. Exploitation requires an administrator-password hash and valid session cookie; the demonstrated consequence is a login.cgi segmentation fault and HTTP 500 response.

The record

CVE
CVE-2026-3613
Published
Mar 6, 2026
Updated
Mar 6, 2026
Vendor
Wavlink
Product
WL-NU516U1
Classifications
CWE-119, T1190
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Mar 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 6, 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=V240425

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Wavlink · WL-NU516U1version=V240425

Published CVSS scores

7.3GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
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

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