Domoticz's MochadTCP::MatchLine() handler for MOCHAD_RFSEC messages (hardware/MochadTCP.cpp) copies network-received data from the up-to-1028-byte m_mochadbuffer into a fixed 50-byte stack buffer tempRFSECbuf using strcpy() with no length check, across three separate code branches (DS10A/KR10A/MS10A device types). An attacker on the local network segment able to reach the Mochad TCP bridge (default port 1099, no authentication) can send a crafted packet that overflows tempRFSECbuf by up to several hundred bytes, corrupting the Domoticz worker thread's stack.