CVE-2026-18746 NULL pointer dereference in Zephyr LwM2M client when the CoAP Block1 context pool is exhausted

parsewriteop in subsys/net/lib/lwm2m/lwm2mmessagehandling.c handles inbound CoAP WRITE/CREATE requests that carry a Block1 option. For the first block of a transfer it called initblockctx and then immediately stored the peer-selected block size with blockctx-ctx.blocksize = blocksize before...