CVE-2026-55606

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

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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 beyond the stack buffer — a single unauthenticated DHCPv6 packet triggers a 2560-byte overread from a 128-byte buffer. At time of publication, there are no publicly available patches.

CVSS 6.5 · Medium · EPSS 0.5%

Published

2026-10-23T13:21:21.038Z

Updated

2026-10-23T13:21:21.038Z

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