PX4-Autopilot provides PX4 flight control solution for drones. In versions 1.14.0-rc1 and prior, PX4-Autopilot has a heap buffer overflow vulnerability in the parser function due to the absence of "parserbuf_index" value checking. A malfunction of the sensor device can cause a heap buffer overflow with leading unexpected drone behavior. Malicious applications can exploit the vulnerability even if device sensor malfunction does not occur. Up to the maximum value of an "unsigned int", bytes sized data can be written to the heap memory area. As of time of publication, no fixed version is available.