# CVE-2026-123590: Hickory DNS DNSSEC signature validation bypass in NSEC/NSEC3

Source: https://junglewise.ai/threats/cve-2026-123590-hickory-dns-hickory-net-0-26-0-beta-1-before-0-26-2-and-hickory  
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-2026-123590 · Severity: medium · CVSS 4.8 · Published 2026-11-08

Hickory DNS is a DNS library that performs DNSSEC validation to verify the authenticity of DNS records. This vulnerability allows attackers who can inject DNS responses to forge nonexistence proofs by mixing validly signed records with forged NSEC/NSEC3 records, potentially causing DNS clients to accept false information about which domains do not exist.

Technologies: [Hickory-Dns Hickory-Net](https://junglewise.ai/threats/technologies/hickory-dns-hickory-net), [Hickory-Dns Hickory-Proto](https://junglewise.ai/threats/technologies/hickory-dns-hickory-proto). Vendors: [Hickory-Dns](https://junglewise.ai/threats/vendors/hickory-dns).

## Quick answers

**Is CVE-2026-123590 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-123590 being exploited in the wild.

**How severe is CVE-2026-123590?** Medium severity, with a CVSS score of 4.8, published 8 November 2026.

**Which products and versions are affected?** Hickory-Dns Hickory-Net 0.26.0-beta.1 before 0.26.2; Hickory-Dns Hickory-Proto through 0.26.0-alpha.1.

**Is there a fix for CVE-2026-123590?** Yes: fixed in hickory-net 0.26.2; hickory-proto fix status unknown. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-123590 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-123590?** Check whether you run Hickory-Dns Hickory-Net or Hickory-Dns Hickory-Proto 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-net 0.26.2; hickory-proto fix status unknown

## Technical details

The vulnerability exists in hickory-net and hickory-proto's DNSSEC validation logic: NSEC and NSEC3 records are accepted if any record with the same owner name passes signature validation, rather than validating each record's signature independently. An attacker with the ability to supply DNS responses can exploit this by including both valid and invalid records with the same name and different types in the authority section, causing bogus NSEC/NSEC3 records to be accepted for nonexistence proofs.

## Affected products

- Hickory DNS hickory-net 0.26.0-beta.1 before 0.26.2
- Hickory DNS hickory-proto through 0.26.0-alpha.1

## Timeline

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

## References

- [https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-57pw-897j-v4j6](https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-57pw-897j-v4j6)
- [https://www.vulncheck.com/advisories/hickory-dns-0.26.0-beta.1-before-0.26.2-improper-nsec-nsec3-signature-validation](https://www.vulncheck.com/advisories/hickory-dns-0.26.0-beta.1-before-0.26.2-improper-nsec-nsec3-signature-validation)

## Related threats

- [Hickory DNS hickory-proto denial of service in BinEncoder](https://junglewise.ai/threats/cve-2026-123608-hickory-dns-hickory-proto-from-0-3-1-before-0-26-1-contains-a)
- [Hickory DNS NSEC3 closest-encloser proof unbounded loop](https://junglewise.ai/threats/cve-2026-123607-hickory-dns-hickory-proto-0-25-0-alpha-3-through-0-25-2-and)
- [Hickory DNS DNSSEC validation bypass via RRSIG Signer's Name](https://junglewise.ai/threats/cve-2026-123605-hickory-dns-hickory-proto-0-1-through-0-25-0-alpha-3-and-hickory)
- [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 NSEC3 comparison operator inversion](https://junglewise.ai/threats/cve-2026-123601-hickory-dns-hickory-proto-0-25-0-through-0-26-0-alpha-1-and)