CVE-2026-42854Patch(espressif / arduino-esp32)

LOWCVSS 9.8 · CRITICAL

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch espressif arduino-esp32 systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD 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.

0.5/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-121

Priority

LOW

Exploitation

NONE

PoC

YES

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • arduino-esp32

Threat summary

  • Patch or workaround signal is available
  • 1 mentions across 1 observed day

What's happening

  • Patch or workaround mentioned in 1 signal
  • 1 total mentions across 1 day

Affected systems

Vendors
Products
arduino-esp32

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-05-12: 1Patch / Workaround · 2026-05-12: 105-12
Signal classification1 categories
Patch
1100.0%
Referenced assets1 URL
By indicator
Full discourse1 post
  • CVE@CVEnew
    Patch

    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 par… https://www.cve.org/CVERecord?id=CVE-2026-42854

    Post summary

    CVE-2026-42854 is a vulnerability in the Arduino ESP32 core that is resolved in version 3.3.8, as indicated by the CVE record link and the reference to the patch version.

    00000123
    57.5K followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
Appespressifarduino-esp32---

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