F´ (F Prime) is a framework that enables development and deployment of spaceflight and other embedded software applications. Prior to 4.2.0, Svc::Ccsds::SpacePacketDeframer dataIn_handler is vulnerable because the handler treats the minimum packet-length condition as FW_ASSERT rather than rejecting and returning the buffer. When a CCSDS telecommand frame leaves a payload of six bytes or fewer after TcDeframer removes its header and trailer, the assertion aborts or resets the flight-software process, causing denial of service. This issue is fixed in version 4.2.0.