Vulnerability Report

CVE-2026-4861

Title: Stack-based Buffer Overflow in Wavlink WL-NU516U1

Memory Corruption

Proof Of Concept

PoC Available for CVE-2026-4861

CWE Category CWE-119
Published Date Mar 26, 2026
Modified Date Apr 30, 2026
Exploit Status Available
Score 7.4 CVSS v4.0
Exploit Probability (EPSS)
0.85%

Vulnerability Summary

CVE-2026-4861: A weakness has been identified in Wavlink WL-NU516U1 260227. This vulnerability affects the function ftext of the file /cgi-bin/nas.cgi. This manipulation of the argument Content-Length causes stack-based buffer overflow. The attack can be initiated remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

Impacted Vendors

W
wavlink 1

Reference Links

https://github.com/Wlz1112/WAVLINK-NU516U1-V260227/blob/main/Content-Length.md https://vuldb.com/?ctiid.353192 https://vuldb.com/?id.353192 https://vuldb.com/?submit.776217
CVSS v4.0
Source Entity [email protected]
Severity HIGH
7.4
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
N/A
RAW VECTOR CVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1
Source Entity [email protected]
Severity HIGH
8.8
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v2.0
Source Entity [email protected]
Severity HIGH
9.0
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:N/AC:L/Au:S/C:C/I:C/A:C

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-4861 Exploits & PoCs (Proof Of Concept)

GitHub https://github.com/HORKimhab/CVE-2026-4861
View Code
MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected Stack

No specific products linked.