CVEvulnerability
CVE-2026-42854
9.8 CRITICAL
Official page ↗
- Status
- Analyzed
- Published
- 2026-05-12
- Last modified
- 2026-10-26
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weaknesses
- 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, 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 configurations
• espressif arduino-esp32 (< 3.3.8)
Related
Weakness · CWE (1)
- CWE-121 Stack-based Buffer Overflow weakness
References
- https://github.com/espressif/arduino-esp32/security/advisories/GHSA-8cmm-3887-r32j Exploit, Vendor Advisory
- https://github.com/espressif/arduino-esp32/security/advisories/GHSA-8cmm-3887-r32j Exploit, Vendor Advisory