CVE-2026-55606
mediumodhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt.
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/openwrt/odhcpd/commit/6907f28f9ddeef9f69f5ee10bbc9ba8adc0ef57f security-advisories@github.com
- https://github.com/openwrt/odhcpd/commit/ed38cffa927d5fd450d20bfd3f7fb8d8e8fff301 security-advisories@github.com
- https://github.com/openwrt/odhcpd/pull/401 security-advisories@github.com
- https://github.com/openwrt/odhcpd/security/advisories/GHSA-x8x4-7gvf-gp45 security-advisories@github.com
- https://github.com/openwrt/odhcpd/security/advisories/GHSA-x8x4-7gvf-gp45 134c704f-9b21-4f2e-91b3-4a467353bcc0