Vulnerability Description
Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-86vr-jm6c-7c
- https://www.vulncheck.com/advisories/hickory-dns-through-0.26.0-alpha.1-dnssec-n
FAQ
What is CVE-2026-123594?
CVE-2026-123594 is a vulnerability with a CVSS score of 4.8 (MEDIUM). Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's...
How severe is CVE-2026-123594?
CVE-2026-123594 has been rated MEDIUM with a CVSS base score of 4.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-123594?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.