CVE-2026-42854 (GCVE-0-2026-42854)

Vulnerability from cvelistv5 – Published: 2026-05-12 21:56 – Updated: 2026-05-13 14:24
VLAI
Title
arduino-esp32: Stack buffer overflow in WebServer multipart boundary parsing leads to remote crash potential RCE
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.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: poc Automatable: yes Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-13 14:24 UTC
CWE
  • CWE-121 - Stack-based Buffer Overflow
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7834 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
espressif arduino-esp32 Affected: < 3.3.8
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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