# CVE-2026-123590: Hickory DNS 0.26.0-beta.1 before 0.26.2 Improper NSEC/NSEC3 Signature Validation

Status: published. Published: 2026-11-08. Updated: 2026-11-08.

Hickory DNS hickory-net 0.26.0-beta.1 before 0.26.2 and hickory-proto through 0.26.0-alpha.1 accept NSEC and NSEC3 records for DNSSEC nonexistence proofs when any other record with the same owner name passes signature validation. Attackers able to supply DNS responses can mix validly signed records with bogus same-name NSEC or NSEC3 records of different types in the authority section to forge nonexistence proofs.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- hickory-dns / hickory-dns (hickory-net): ≥ 0.26.0-beta.1; < 0.26.2 (affected, semver); 0.26.2 (unaffected, semver). Source: CNA: VulnCheck
- hickory-dns / hickory-dns (hickory-proto): ≥ 0; ≤ 0.26.0-alpha.1 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 6.3 (medium); CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 4.8 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-347

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-57pw-897j-v4j6 (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/hickory-dns-0.26.0-beta.1-before-0.26.2-improper-nsec-nsec3-signature-validation (CNA: VulnCheck; third-party-advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-123590; retrieved 2026-11-08; source updated 2026-11-08

Revision: 878c52ba010fe1efbf00b5b9a2dd78f90c4a694a193955d12357979a29e9851c

Canonical: https://y2.dev/cve/CVE-2026-123590

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