PatchTheCVECVE-2026-53920: odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt
CVE-2026-53920 is a high-severity flaw (CVSS 8.7) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt. From version 17.01.0 to before version 25.12.3, odhcpd's DHCPv6 IA parser accepts an IA_NA or IA_PD option whose body is shorter than struct dhcpv6_ia_hdr, casts the option header to that full structure, and reads ia->iaid before proving that the IA body contains the IAID field. If an unauthenticated network-adjacent client places a zero-length or otherwise short IA op
Why this priority
- High severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-53920?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-53920 being exploited?
CVE-2026-53920 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-53920 affect?
CVE-2026-53920 affects affected software. Severity is high (CVSS 8.7). odhcpd is the DHCPv6, DHCPv4, and router-advertisement server used by OpenWrt. From version 17.01.0 to before version 25.12.3, odhcpd's DHCPv6 IA parser accepts an IA_NA or IA_PD option whose body is shorter than struct dhcpv6_ia_hdr, casts
How urgent is CVE-2026-53920?
Priority 46/100. High severity; Remotely exploitable, no login, no user action