CVE-2026-55606
odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt
- Risk score
- 47/100
- CVSS
- 6.5 v3.1
- Exploit chance (30 days)
- 0.5%
- Published
- 23 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- 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 …
- Affected
- See advisory
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 6.5 medium
References
Original description
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.
Last activity 23 Oct 2026. Patch Forecast updates every hour.