CVE-2026-41429 Improper validation of NBNS name_len in arduino-esp32 NetBIOS leads to memory corruption
Remote attackers can trigger memory corruption in ESP32 devices via crafted NBNS packets when NetBIOS is enabled, potentially leading to code execution or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-41429?
CVE-2026-41429 is a high-severity memory corruption vulnerability in espressif arduino-esp32, published on 24 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-121
Which versions are affected by CVE-2026-41429?
It affects 1 product.
Products include Espressif Arduino-Esp32.
How do I fix CVE-2026-41429?
No fix has been published for CVE-2026-41429 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-41429 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41429 exists.
Other vulnerabilities in espressif arduino-esp32
Sources
Also known as GHSA-92j9-c75g-2c5f.