8.3
HIGH CVSS 4.0
CVE-2026-41927
WDR201A WiFi Extender Stack-Based Buffer Overflow via firewall.cgi
Description

WDR201A WiFi Extender (HW V2.1, FW LFMZX28040922V1.02) contains a stack-based buffer overflow vulnerability in the firewall.cgi and makeRequest.cgi binaries that allows unauthenticated attackers to overwrite the saved return address by sending a POST request with a Content-Length header exceeding 512 bytes. Attackers can exploit insufficient length validation in the fgets() call to achieve arbitrary code execution through return-oriented programming or return-to-libc techniques.

INFO

Published Date :

May 4, 2026, 8:16 p.m.

Last Modified :

May 4, 2026, 8:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-41927 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 4.0 HIGH [email protected]
Solution
Fix buffer overflow in firewall.cgi and makeRequest.cgi by validating input length.
  • Update firewall.cgi and makeRequest.cgi binaries.
  • Implement strict input length validation.
  • Apply vendor-provided firmware updates.
  • Avoid sending excessively long POST requests.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-41927 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-41927 weaknesses.

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-2026-41927 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-41927 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]

    May. 04, 2026

    Action Type Old Value New Value
    Added Description WDR201A WiFi Extender (HW V2.1, FW LFMZX28040922V1.02) contains a stack-based buffer overflow vulnerability in the firewall.cgi and makeRequest.cgi binaries that allows unauthenticated attackers to overwrite the saved return address by sending a POST request with a Content-Length header exceeding 512 bytes. Attackers can exploit insufficient length validation in the fgets() call to achieve arbitrary code execution through return-oriented programming or return-to-libc techniques.
    Added CVSS V4.0 AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/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 CWE CWE-121
    Added Reference https://mstreet97.github.io/security-research/iot/vulnerability-disclosure/ai-assisted-research/cybersecurity/cve/2026/05/04/Teaching_the_Machine_Where_to_Look.html
    Added Reference https://www.made-in-china.com/showroom/yeapook/#:~:text=Established%20in%202015.%2CDistrict%2C%20Shenzhen%2C%20Guangdong%2C%20China
    Added Reference https://www.vulncheck.com/advisories/wdr201a-wifi-extender-stack-based-buffer-overflow-via-firewall-cgi
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.