Stack-based Buffer Overflow Vulnerability in Wavlink Product
CVE-2026-4861

8.7HIGH

Key Information:

Vendor

Wavlink

Status
Wl-nu516u1
Vendor
CVE Published:
26 March 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-4861?

A vulnerability has been discovered in the Wavlink WL-NU516U1 device, specifically affecting the function ftext located in the /cgi-bin/nas.cgi file. This issue arises due to improper handling of the Content-Length argument, leading to a stack-based buffer overflow. Attackers can exploit this vulnerability remotely, potentially enabling unauthorized access and control over the affected device. Publicly available exploit details heighten the urgency for users to assess their security posture. Despite early notifications, the vendor has yet to respond to this critical disclosure.

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Affected Version(s)

WL-NU516U1 260227

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-4861 - Proof of Concept

References

https://vuldb.com/?id.353192
vdb-entrytechnical-description
https://vuldb.com/?ctiid.353192
signaturepermissions-required
https://vuldb.com/?submit.776217
third-party-advisory

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

haimianbaobao (VulDB User)
VulDB
JSON
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