CVE-2026-41429

HIGH
Published Apr 24, 2026 Modified May 5, 2026 CWE-121

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.

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CVSS v3.1 Score

8.8
HIGH
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0002
Probability of exploitation
0.05%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-121 CWE-121

Affected Products

Vendor Product
espressif arduino-esp32
espressif esp32
espressif esp32-c3
espressif esp32-c6
espressif esp32-h2
espressif esp32-s2
espressif esp32-s3

References

Frequently Asked Questions

What is CVE-2026-41429? +
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. It has a CVSS v3.1 base score of 8.8 (HIGH).
How severe is CVE-2026-41429? +
CVE-2026-41429 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0002, placing it in the 0th percentile for exploitation probability.
What products are affected by CVE-2026-41429? +
CVE-2026-41429 affects products from espressif, specifically: arduino-esp32, esp32, esp32-c3, esp32-c6, esp32-h2, esp32-s2, esp32-s3. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2026-41429? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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