CVE-2026-18747

The MCUmgr SMP-over-console transport decodes a base64 frame, reads a 16-bit packet length from it, verifies a CRC and then unconditionally strips the trailing CRC with rxctxt-nb-len -= 2U; in mcumgrserialprocessfrag subsys/mgmt/mcumgr/transport/src/serialutil.c. mcumgrserialextractlen accepted a...