9.0
HIGH CVSS 2.0
CVE-2026-4861
Wavlink WL-NU516U1 nas.cgi ftext stack-based overflow
Description

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.

INFO

Published Date :

March 26, 2026, 9:16 a.m.

Last Modified :

March 26, 2026, 9:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-4861 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 2.0 HIGH [email protected]
CVSS 3.1 HIGH [email protected]
CVSS 4.0 HIGH [email protected]
Solution
Stack-based buffer overflow in /cgi-bin/nas.cgi due to Content-Length argument manipulation.
  • Apply vendor patches when available.
  • Monitor network for suspicious Content-Length values.
  • Consider disabling the nas.cgi service if not needed.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-4861.

URL Resource
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
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-4861 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-4861 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-4861 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Mar. 26, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CVSS V4.0 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
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Added CVSS V2 (AV:N/AC:L/Au:S/C:C/I:C/A:C)
    Added CWE CWE-119
    Added CWE CWE-121
    Added Reference https://github.com/Wlz1112/WAVLINK-NU516U1-V260227/blob/main/Content-Length.md
    Added Reference https://vuldb.com/?ctiid.353192
    Added Reference https://vuldb.com/?id.353192
    Added Reference https://vuldb.com/?submit.776217
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.