cvedb.io
CVE-2026-42854
CRITICAL · CVSS 9.8
EPSS exploitation probability: 0%
Published 2026-05-12T22:16:34.930 · Last modified 2026-06-17T10:48:30.760

Summary

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, the WebServer multipart form parser in arduino-esp32 allocates a Variable Length Array (VLA) on the stack whose size is derived from an attacker-controlled HTTP header field (Content-Type: multipart/form-data; boundary=...) without enforcing any length limit. Sending a boundary string longer than ~8000 characters overflows the 8192-byte task stack of the loopTask, causing a crash and potential remote code execution. This vulnerability is fixed in 3.3.8.

Affected products

espressif — arduino-esp32

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.