CVE-2026-55606Published

odhcpd: Stack buffer overread via DUID length endianness mismatch in memcmp()

Exact source revision recorded 23 Oct 2026 16:01:20 UTC. It does not establish the source's current position. Latest evidence.

Recorded JSON

cve-program · CVE-2026-55606

Published

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.

Source published: 23 Oct 2026 13:21:21 UTC
Source modified: 23 Oct 2026 13:21:21 UTC
Observed here: 23 Oct 2026 16:01:20 UTC
Source terms: CVE Program Terms of Use

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CVSS 3.1 · 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L