CVE-2026-42854 arduino-esp32: Stack buffer overflow in WebServer multipart boundary parsing leads to remote crash potential RCE

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 head...

CVE-2026-42854 arduino-esp32: Stack buffer overflow in WebServer multipart boundary parsing leads to remote crash potential RCE

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 head...

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 whose size is derived from an attacker-controlled HTTP head...

CVE-2026-42854

Summary: The Arduino-ESP32 core is affected by a stack overflow in the WebServer multipart boundary parser. A boundary derived from the HTTP header (Content-Type: multipart/form-data; boundary=...) with length > ~8000 can overflow the 8192-byte loopTask stack, potentially enabling remote code ...

CVE-2026-42854 arduino-esp32: Stack buffer overflow in WebServer multipart boundary parsing leads to remote crash potential RCE

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 head...

CVE-2026-42855 arduino-esp32: Digest authentication URI mismatch bypass in WebServer allows cross-resource replay attack

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 Digest authentication implementation in arduino-esp32 computes the authentication hash using the URI field from the client's Authorization header,...

CVE-2026-42855

The vulnerability affects the arduino-esp32 core (WebServer Digest authentication). Before version 3.3.8, the Digest auth hash is computed from the URI field in the Authorization header without validating it against the actually requested URI. As a result, an attacker with any valid digest respon...

EUVD-2026-29859

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 Digest authentication implementation in arduino-esp32 computes the authentication hash using the URI field from the client's Authorization header,...

CVE-2026-42855

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 Digest authentication implementation in arduino-esp32 computes the authentication hash using the URI field from the client's Authorization header,...

CVE-2026-42855 arduino-esp32: Digest authentication URI mismatch bypass in WebServer allows cross-resource replay attack

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 Digest authentication implementation in arduino-esp32 computes the authentication hash using the URI field from the client's Authorization header,...

CVE-2026-42855 arduino-esp32: Digest authentication URI mismatch bypass in WebServer allows cross-resource replay attack

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 Digest authentication implementation in arduino-esp32 computes the authentication hash using the URI field from the client's Authorization header,...

CVE-2026-42855

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 Digest authentication implementation in arduino-esp32 computes the authentication hash using the URI field from the client's Authorization header,...

CVE-2026-42855: Improper Authentication

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 Digest authentication implementation in arduino-esp32 computes the authentication hash using the URI field from the client's Authorization header,...

PT-2026-40455

Name of the Vulnerable Software and Affected Versions arduino-esp32 versions prior to 3.3.8 Description The WebServer Digest authentication implementation computes the authentication hash using the URI field from the client's Authorization header without verifying that it matches the actual...

arduino-esp32 安全漏洞

Arduino-ESP32 is an open-source project by Espressif, designed for use with the ESP32, ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6, and ESP32-H2 boards. Versions of Arduino-ESP32 prior to 3.3.8 contained a security vulnerability. This vulnerability stemmed from the WebServer multi-part form parser’s...

CVE-2026-42854: Stack-based Buffer Overflow

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 head...

PT-2026-40454

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 head...

CVE-2026-41429 Improper validation of NBNS name_len in arduino-esp32 NetBIOS leads to memory corruption

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, there is a remotely reachable memory corruption issue in the NBNS packet handling path. When NetBIOS is enabled by calling NBNS.begin..., the device listens on UDP...

CVE-2026-41429 Improper validation of NBNS name_len in arduino-esp32 NetBIOS leads to memory corruption

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, there is a remotely reachable memory corruption issue in the NBNS packet handling path. When NetBIOS is enabled by calling NBNS.begin..., the device listens on UDP...

CVE-2026-41429

CVE-2026-41429 affects the arduino-esp32 core (ESP32/ESP32-S2/ESP32-S3/ESP32-C3/ESP32-C6/ESP32-H2). The issue is a memory corruption in NBNS packet handling when NetBIOS is enabled via NBNS.begin(...); the code path listens on UDP port 137 and processes untrusted NBNS requests. The request parser...