A vulnerability in quinn-udp's receive loop can cause it to spin indefinitely after receiving a truncated datagram when the receive buffer is smaller than the incoming datagram. This affects certain platforms that read one datagram per recvmsg call and do not rebuild the message header on each call, causing the loop to repeatedly issue non-blocking receives without returning a WouldBlock error. The issue is fixed in versions 0.5.16 and 0.6.3.