Quick answers
- Is CVE-2026-55606 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-55606 being exploited in the wild.
- How severe is CVE-2026-55606?
- Medium severity, with a CVSS score of 6.5, published 23 October 2026.
- Which products and versions are affected?
- OpenWrt Odhcpd 25.12 and prior.
- Is there a fix for CVE-2026-55606?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-55606 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-55606?
- Check whether you run OpenWrt Odhcpd at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is an out-of-bounds read in dhcpv6.c:720 where a network-byte-order DUID length value is passed directly to memcmp() instead of being converted to host byte order. On little-endian systems, this causes memcmp() to read up to 3584 bytes from a 128–130 byte stack buffer. An unauthenticated attacker can trigger this via a single crafted DHCPv6 packet. The fix requires converting the length using ntohs() before passing it to memcmp().
Affected products
- OpenWrt odhcpd 25.12 and prior
Timeline
- 2026-10-23: disclosed