8.8
HIGH CVSS 3.1
CVE-2026-41429
Improper validation of NBNS name_len in arduino-esp32 NetBIOS leads to memory corruption
Description

arduino-esp32 is an Arduino core for the ESP32, ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6 and ESP32-H2 microcontrollers. Prior to 3.3.8, there is a remotely reachable memory corruption issue in the NBNS packet handling path. When NetBIOS is enabled by calling NBNS.begin(...), the device listens on UDP port 137 and processes untrusted NBNS requests from the local network. The request parser trusts the attacker-controlled name_len field without enforcing a bound consistent with the fixed-size destination buffers used later in the flow. This vulnerability is fixed in 3.3.8.

INFO

Published Date :

April 24, 2026, 8:16 p.m.

Last Modified :

April 24, 2026, 8:16 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-41429 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 3.1 HIGH [email protected]
Solution
Update arduino-esp32 to version 3.3.8 or later to fix memory corruption in NBNS packet handling.
  • Update arduino-esp32 core to version 3.3.8.
  • Ensure NetBIOS is disabled 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-2026-41429.

URL Resource
https://github.com/espressif/arduino-esp32/security/advisories/GHSA-92j9-c75g-2c5f
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-41429 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-2026-41429 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-2026-41429 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-41429 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]

    Apr. 24, 2026

    Action Type Old Value New Value
    Added Description arduino-esp32 is an Arduino core for the ESP32, ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6 and ESP32-H2 microcontrollers. Prior to 3.3.8, there is a remotely reachable memory corruption issue in the NBNS packet handling path. When NetBIOS is enabled by calling NBNS.begin(...), the device listens on UDP port 137 and processes untrusted NBNS requests from the local network. The request parser trusts the attacker-controlled name_len field without enforcing a bound consistent with the fixed-size destination buffers used later in the flow. This vulnerability is fixed in 3.3.8.
    Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-121
    Added Reference https://github.com/espressif/arduino-esp32/security/advisories/GHSA-92j9-c75g-2c5f
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.