# CVE-2026-123602: Hickory DNS recursor cache poisoning via ghost domain attack

Source: https://junglewise.ai/threats/cve-2026-123602-the-hickory-dns-recursor-in-all-versions-of-hickory-recursor-and  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-08. Updated: 2026-11-08  
License: CC BY 4.0 with a link back

CVE-2026-123602 · Severity: medium · CVSS 5.9 · Published 2026-11-08

Hickory DNS is a domain name system resolver library used by applications to translate domain names into IP addresses. A vulnerability allows attackers to poison the resolver's cache by repeatedly querying DNS records, causing it to use outdated name servers even after a domain's delegation has been revoked. This could result in DNS hijacking or denial of service for affected domains.

Technologies: [Hickory-Dns Hickory-Recursor](https://junglewise.ai/threats/technologies/hickory-dns-hickory-recursor), [Hickory-Dns Hickory-Resolver](https://junglewise.ai/threats/technologies/hickory-resolver). Vendors: [Hickory-Dns](https://junglewise.ai/threats/vendors/hickory-dns).

## Quick answers

**Is CVE-2026-123602 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-123602 being exploited in the wild.

**How severe is CVE-2026-123602?** Medium severity, with a CVSS score of 5.9, published 8 November 2026.

**Which products and versions are affected?** Hickory-Dns Hickory-Recursor all versions; Hickory-Dns Hickory-Resolver 0.26.0-beta.1 before 0.26.2 (recursor feature).

**Is there a fix for CVE-2026-123602?** Yes: fixed in hickory-resolver 0.26.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-123602 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-123602?** Check whether you run Hickory-Dns Hickory-Recursor or Hickory-Dns Hickory-Resolver 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.

## How to fix

- Fixed in hickory-resolver 0.26.2

## Technical details

The vulnerability is a cache poisoning flaw (CWE-672) in the DNS recursor's handling of child-side apex NS RRsets. When processing zone NS queries, the resolver caches the apex NS record set and reuses it for iterative resolution. An attacker can keep this RRset cached indefinitely through repeated queries, allowing revoked name servers to continue answering for a zone. This is a variant of CVE-2012-1033 and CVE-2022-30698.

## Affected products

- Hickory DNS hickory-recursor all versions
- Hickory DNS hickory-resolver 0.26.0-beta.1 before 0.26.2 (recursor feature)

## Timeline

- 2026-09-03: disclosed
- 2026-11-08: advisory

## References

- [https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-2hxp-x833-73f7](https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-2hxp-x833-73f7)
- [https://www.vulncheck.com/advisories/hickory-dns-recursor-ghost-domain-attack-via-child-side-ns-rrset-caching](https://www.vulncheck.com/advisories/hickory-dns-recursor-ghost-domain-attack-via-child-side-ns-rrset-caching)

## Related threats

- [hickory-dns recursor glueless-NS referral amplification](https://junglewise.ai/threats/cve-2026-123606-the-hickory-dns-recursor-in-hickory-recursor-0-25-0-alpha-3)
- [Hickory DNS hickory-resolver unbounded retry loop resource exhaustion](https://junglewise.ai/threats/cve-2026-123604-hickory-dns-hickory-resolver-0-26-0-beta-1-before-0-26-2)
- [Hickory DNS IPv4-mapped IPv6 canonicalization bypass](https://junglewise.ai/threats/cve-2026-123603-hickory-proto-and-hickory-resolver-0-26-0-before-0-26-2-hickory)
- [Hickory DNS recursive resolver denial of service via cached empty connection pool](https://junglewise.ai/threats/cve-2026-123588-the-recursive-resolver-in-hickory-dns-all-versions-of-the)
- [Hickory DNS query amplification in recursive resolver](https://junglewise.ai/threats/cve-2026-123586-hickory-dns-0-25-0-alpha-3-through-0-25-2-contains-a-query)