What is CVE-2026-123606?

CVE-2026-123606 is a high-severity vulnerability in Hickory-Dns, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-11-08.

How severe is CVE-2026-123606?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Hickory-Dns

CVE-2026-123606

The hickory-dns recursor in hickory-recursor 0.25.0-alpha.3 through 0.25.2 and hickory-resolver 0.26.0-alpha.1 before 0.26.2 iterates every out-of-bailiwick NS target lacking glue in a referral without any per-query work budget. Remote attackers can serve such referrals to force A and AAAA lookups per target, amplifying traffic against remote servers or exhausting recursor resources.

Vulnerability class: DoS (Denial of Service)

Published 2026-11-08.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Hickory-Dns

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

References

GitHub Security Advisory (GHSA-6h5c-jjg5-wj59) (vendor-advisory)
VulnCheck Advisory: Hickory-DNS Recursor 0.25.0-alpha.3 through 0.25.2 Glueless-NS Referral Amplification (third-party-advisory)

Frequently asked questions

What is CVE-2026-123606?: CVE-2026-123606 is a high-severity vulnerability in Hickory-Dns, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-11-08.
How severe is CVE-2026-123606?: High severity. CVSS v3 base score is 7.5 out of 10.