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CVE-2026-123596

8.8, high

Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain a DNSSEC validation flaw in the…

NVD (opens in a new tab) CVE.org (opens in a new tab)
CVSS
8.8, high high CVSS v3.1
EPSS, next 30 days
n/a
Exploitation
No public evidence
Published
8 Nov 2026today

Description

Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain a DNSSEC validation flaw in the validating recursor's NSEC handler that accepts parent-side ancestor-delegation NSEC records as proof of nonexistence for names below the zone cut. An on-path attacker, rogue parent nameserver, or attacker winning a port and TXID race can deliver one forged NXDOMAIN response built from genuinely signed parent NSEC records, causing authenticated denial of existing child-zone names cached for the negative TTL.

Details

Vendor
Hickory-dns
Product
hickory-dns
Weakness
CWE-345 (opens in a new tab)
Status
Received
Updated
8 Nov 2026
Assigner
disclosure@vulncheck.com

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References 2

Advisories 1

Other references 1

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other Hickory-dns CVEs

Every Hickory-dns CVE we hold

Same vendor in what we hold, not a known link between the flaws.

  • CVE-2026-123570 hickory-dns Uncontrolled Resource Consumption Vulnerability 7.5, high
  • CVE-2026-123571 hickory-dns Integer Underflow Vulnerability 7.5, high
  • CVE-2026-123572 Hickory-dns from 0.20.1 before 0.26.2 contains a denial of service vulnerability in the hickory-proto SVCB and HTTPS record presentation… 7.5, high
  • CVE-2026-123573 hickory-dns Improper Input Validation Vulnerability 7.5, high
  • CVE-2026-123574 hickory-dns Improper Input Validation Vulnerability 7.5, high
  • CVE-2026-123575 hickory-dns Allocation of Resources Without Limits or Throttling Vulnerability 7.5, high
  • CVE-2026-123576 hickory-dns Allocation of Resources Without Limits or Throttling Vulnerability 7.5, high
  • CVE-2026-123577 hickory-dns Allocation of Resources Without Limits or Throttling Vulnerability 7.5, high

Beyond this page

Is CVE-2026-123596 in your network?

This page tells you how dangerous CVE-2026-123596 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

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    Find it before attackers do

    Ocelot scans your network on a schedule and reports every vulnerability it finds by its CVE identifier, with its CVSS score and how many of your hosts are affected. A finding like CVE-2026-123596 comes with the devices to patch.

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  • EXYS7950 KONDRA

    Detect it if it's exploited

    Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.

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Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 8 Nov 2026, not the live upstream state.