Strix
73.1K

CVE-2026-55606

MEDIUMCVSS 6.5/10EPSS 0.38%

Last modified

CVE-2026-55606 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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. EPSS estimates a 0.38% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
6.5/10

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

EPSS Probability
0.38%

31.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
openwrtodhcpd<= 25.12

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-55606?
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.
How severe is CVE-2026-55606?
CVE-2026-55606 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.38% probability of exploitation in the next 30 days.
How do I fix CVE-2026-55606?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

View all 2026CVEs →

Are you affected by CVE-2026-55606?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST