CVE-2025-69209

CVE-2025-69209 describes a stack-based buffer overflow in ArduinoCore-avr versions prior to 1.8.7, affecting AVR-based Arduino boards. An attacker can trigger this vulnerability by providing very large decimalPlaces values to String constructors or concat methods when converting floating-point numbers, leading to memory corruption and denial of service. While the attack complexity is low and no user interaction is required, it typically requires local access to the device. Under specific conditions, this could enable arbitrary code execution. Currently, there is no evidence of active exploitation, public exploit code, or significant community discussion surrounding this vulnerability.