CVE-2026-42854
CRITICAL EPSS 42.9%
Published May 12, 20261mo ago · Modified Jun 17, 20261w ago
9.8 CVSS 3.1
Published May 12, 2026 1mo ago
Last Modified Jun 17, 2026 1w ago
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High
Threat Intelligence
EPSS Exploit Probability
42.9% percentile
Exploit & Patch Status
Public Exploit Known
No Patch Available
Weaknesses 1
CWE-121
Affected Products 1
| Vendor | Product | Version | Range |
|---|---|---|---|
| espressif | arduino-esp32 | * | <3.3.8 |
References 1
- github.com https://github.com/espressif/arduino-esp32/security/advisories/GHSA-8cmm-3887-r32j
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.