Buffer overflow in Espressif Arduino-esp32
CVE-2026-42854
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…
Vulnerability class: Buffer Overflow
EPSS: 0.003 (52.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Espressif Arduino-esp32 — versions < 3.3.8
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-42854?
- CVE-2026-42854 is a critical-severity vulnerability in Espressif Arduino-esp32, classified under Stack-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-05-12.
- How severe is CVE-2026-42854?
- Critical severity. CVSS v3 base score is 9.8 out of 10.