CVE-2026-55606 odhcpd: Stack buffer overread via DUID length endianness mismatch in memcmp()

odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt. In versions 25.12 and prior, odhcpd's DHCPv6 self-loop detection at dhcpv6.c:720 uses a network-byte-order DUID length value directly as the memcmp size parameter. On little-endian hosts, this causes memcmp to read far...