Quick answers
- Is CVE-2026-123591 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-123591 being exploited in the wild.
- How severe is CVE-2026-123591?
- Medium severity, with a CVSS score of 5.9, 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-2026-123591?
- Yes: fixed in hickory-net 0.26.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-123591 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-123591?
- 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
Technical details
The vulnerability is an insufficient verification of data authenticity (CWE-345) in DNSSEC validation logic. When validating insecure delegations, hickory-net and hickory-proto fail to check RFC 6840 §4.4 requirements: that NSEC/NSEC3 records proving no DS record exists must also prove the delegation's NS record exists. An attacker can reuse NSEC/NSEC3 records from the child zone to falsely prove an insecure delegation and forge other child zone records.
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: GitHub security advisory published
- 2026-11-08: advisory: NVD entry published