CVE-2025-69209

ArduinoCore-avr contains the source code and configuration files of the Arduino AVR Boards platform. A vulnerability in versions prior to 1.8.7 allows an attacker to trigger a stack-based buffer overflow when converting floating-point values to strings with high precision. By passing very large `decimalPlaces` values to the affected String constructors or concat methods, the `dtostrf` function writes beyond fixed-size stack buffers, causing memory corruption and denial of service. Under specific conditions, this could enable arbitrary code execution on AVR-based Arduino boards. ### Patches - The Fix is included starting from the `1.8.7` release available from the following link ArduinoCore-avr v1.8.7 - The Fixing Commit is available at the following link 1a6a417f89c8901dad646efce74ae9d3ddebfd59 ### References - ASEC-26-001 ArduinoCore-avr vXXXX Resolves Buffer Overflow Vulnerability ### Credits - Maxime Rossi Bellom and Ramtine Tofighi Shirazi from SecMate (https://secmate.dev/)