What is CVE-2026-123602?

CVE-2026-123602 is a medium-severity vulnerability in Hickory-Dns, classified under Operation on a Resource after Expiration or Release. CVSS score: 5.9/10. Published 2026-11-08.

How severe is CVE-2026-123602?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Vulnerability in Hickory-Dns

CVE-2026-123602

The Hickory DNS recursor in all versions of hickory-recursor and in hickory-resolver 0.26.0-beta.1 before 0.26.2 (recursor feature) is vulnerable to ghost domain names attacks because it reuses child-side apex NS RRsets cached from zone NS queries for iterative resolution. By repeatedly querying a zone's NS records, an attacker keeps the stale RRset cached indefinitely, letting name servers whose delegation the parent revoked keep answering for the zone.

Published 2026-11-08.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.003 (19.6th percentile), scored 2026-11-09.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 19.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

Hickory-Dns

Weakness classification (CWE)

CWE-672 — Operation on a Resource after Expiration or Release

References

github.com/hickory-dns/hickory-dns/security/advisories/GHSA-2hxp-x833-73f7 (vendor-advisory)
www.vulncheck.com/advisories/hickory-dns-recursor-ghost-domain-attack-via-child… (third-party-advisory)

Frequently asked questions

What is CVE-2026-123602?: CVE-2026-123602 is a medium-severity vulnerability in Hickory-Dns, classified under Operation on a Resource after Expiration or Release. CVSS score: 5.9/10. Published 2026-11-08.
How severe is CVE-2026-123602?: Medium severity. CVSS v3 base score is 5.9 out of 10.