PT-2026-40454 · Espressif Systems · Arduino-Esp32

Published 2026-05-12 · Updated 2026-05-12 · CVE-2026-42854

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions arduino-esp32 versions prior to 3.3.8

Description The WebServer multipart form parser allocates a Variable Length Array (VLA)—an array whose size is determined at runtime—on the stack. The size of this array is derived from the boundary parameter within the Content-Type HTTP header field without any length enforcement. An attacker can send a boundary string exceeding approximately 8000 characters to overflow the 8192-byte task stack of the loopTask() function, leading to a system crash and potential remote code execution.

Recommendations Update to version 3.3.8.

Exploit

Fix

RCE

Stack Overflow

Weakness Enumeration

CWE-121

Related Identifiers

CVE-2026-42854

Affected Products

Arduino-Esp32

References · 3

• 🔥 https://github.com/espressif/arduino-esp32/security/advisories/GHSA-8cmm-3887-r32j · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-42854 · Security Note
• https://t.me/CVEtracker/53547 · Telegram Post