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.
Affected products
espressif: arduino-esp32; espressif: esp32; espressif: esp32-c3; espressif: esp32-c6; espressif: esp32-h2; espressif: esp32-s2; espressif: esp32-s3
References2
- github.com/espressif/arduino-esp32/security/advisories/GHSA-92j… ExploitVendor Advisory
- github.com/espressif/arduino-esp32/security/advisories/GHSA-92j… ExploitVendor Advisory
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: CNA
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 24 · as of 13 November 2026
- CWE
- CWE-121
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.