CVE-2026-123596

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.

Overview

State: PUBLISHED
Assigner (CNA): VulnCheck
CVSS severity: HIGH
CVSS score: 8.7 / 10
CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Effective score: 8.7 / 10 HIGH source: CNA overview
CWE(s): CWE-345
Reserved: 2026-11-06
Published: 2026-11-08 01:38 UTC
Last updated: 2026-11-08 01:38 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/123xxx/CVE-2026-123596.json
Linked Threat: CVE-2026-123596 — Hickory DNS through 0.26.0-alpha.1 DNSSEC Validation Bypass via Ancestor-Delegation NSEC

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-119355

EUVD enrichment is queued; refresh the page in a few seconds.

Affected products (2)

Vendor	Product	Versions	Platforms
hickory-dns	hickory-dns	`0` (affected)	—
hickory-dns	hickory-dns	`0.26.0-beta.1` (affected), `0.26.2` (unaffected)	—

Vendor references (2)

References embedded in the original CVE record by the assigning CNA.

GitHub Security Advisory (GHSA-3r6v-f3jh-vvqm) vendor-advisory
VulnCheck Advisory: Hickory DNS through 0.26.0-alpha.1 DNSSEC Validation Bypass via Ancestor-Delegation NSEC third-party-advisory

Web references (0)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

No web references attached yet.

Remediations (10)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

PHP CVE-2026-109618 and CVE-2026-109619: Patch Status and Workarounds

web:codykretsinger.com

They fix two critical vulnerabilities, both rated 9.2 on CVSS v4.0, that can allow unauthenticated remote code execution: CVE - 2026 -109618, RCE via OOM corruption. PHP's out-of-memory handling can interrupt a request while internal data is only partly initialized, and request cleanup can then treat that data as valid.

2026-11-08 10:22 UTC
CVE Vulnerabilities 2026: Critical Flaws & Fixes Hub

web:cyberupdates365.com

Track critical CVE vulnerabilities 2026 with verified enterprise patch guides. Fix zero-days across VMware, WordPress, Windows, and cloud infrastructure.

2026-11-08 10:22 UTC
ArcGIS Server Security 2026 Update 4 Patch - Esri Support

web:support.esri.com

The issues resolved by these patches are listed in the Issues addressed with this patch section below. As part of the patch installation, the ArcGIS Server service is stopped and restarted. The restart may take several minutes depending on the number of services published on the ArcGIS Server site. This patch can be uninstalled as outlined in the Uninstalling this patch on Windows and ...

2026-11-08 10:22 UTC
[Security Advisory] September 2026 CVE Advisory Notification

web:support.servicenow.com

What you need to know: On September 24, 2026 , ServiceNow issued CVE - 2026 -86857, CVE - 2026 -86858, CVE - 2026 -13016, CVE - 2026 -86859, and CVE - 2026 -86860. Each of these security issues was identified through internal security testing, customer security assessments, or reports submitted through ServiceNow's responsible disclosure and bug bounty programs and was remediated independently. For security ...

2026-11-08 10:22 UTC
Addressing PHP2Shell CVE-2026-109618 and CVE-2026-109619: upgrade ...

web:techcommunity.microsoft.com

Learn more: Azure WAF custom rules for PHP2Shell mitigation . Request-side signals alone may not be sufficient to reliably identify certain exploitation attempts. Signals in the server response can provide additional evidence that malicious activity has occurred, enabling more targeted mitigation with higher confidence and lower false positives.

2026-11-08 10:22 UTC
CVE-2026-123596 - DNSSEC Validation Flaw in Hickory DNS…

web:vulmon.com

Vulnerability Summary Hickory DNS versions before 0.26.2, including hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1, have a DNSSEC validation flaw. This flaw allows an on-path attacker, a rogue parent nameserver, or an attacker winning a port and TXID race to deliver a forged NXDOMAIN response. This forged response, built from signed parent NSEC records, can cause ...

2026-11-08 10:22 UTC
What Is CVE Remediation in 2026? - aikido.dev

web:www.aikido.dev

CVE remediation is fixing known flaws in the software you run. Why upgrading often fails, what remediation actually involves, and how backporting fixes it.

2026-11-08 10:22 UTC
Critical PHP RCE Vulnerabilities: Patch Now (CVE-2026 ... - DigitalOcean

web:www.digitalocean.com

Two critical PHP remote code execution vulnerabilities ( CVE - 2026 -109618, CVE - 2026 -109619) were disclosed Oct 21, 2026 . See what's affected and how to patch .

2026-11-08 10:22 UTC
The 8 Best Automated Vulnerability Remediation Tools in 2026

web:www.openhands.dev

Compare 8 automated vulnerability remediation tools for 2026 on fixes, prioritization, integrations, and deployment control.

2026-11-08 10:22 UTC
Oracle Critical Patch Update Advisory - October 2026

web:www.oracle.com

This Critical Patch Update contains 1295 new security patches across the product families listed below. Please note that a My Oracle Support (MOS) note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at October 2026 Critical Patch Update: Executive Summary and Analysis.

2026-11-08 10:22 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-123596.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:cargo/hickory-proto",
          "product": "hickory-dns",
          "vendor": "hickory-dns",
          "versions": [
            {
              "lessThanOrEqual": "0.26.0-alpha.1",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:cargo/hickory-net",
          "product": "hickory-dns",
          "vendor": "hickory-dns",
          "versions": [
            {
              "lessThan": "0.26.2",
              "status": "affected",
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              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "0.26.2",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "qifan-sailboat"
        }
      ],
      "datePublic": "2026-09-03T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
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        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "LOW",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
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            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
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          "cvssV3_1": {
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            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-345",
              "description": "Insufficient Verification of Data Authenticity",
              "lang": "en",
              "type": "CWE"
            }
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        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-08T01:38:25.747Z",
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      },
      "references": [
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          "name": "GitHub Security Advisory (GHSA-3r6v-f3jh-vvqm)",
          "tags": [
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          ],
          "url": "https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-3r6v-f3jh-vvqm"
        },
        {
          "name": "VulnCheck Advisory: Hickory DNS through 0.26.0-alpha.1 DNSSEC Validation Bypass via Ancestor-Delegation NSEC",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/hickory-dns-through-0.26.0-alpha.1-dnssec-validation-bypass-via-ancestor-delegation-nsec"
        }
      ],
      "title": "Hickory DNS through 0.26.0-alpha.1 DNSSEC Validation Bypass via Ancestor-Delegation NSEC",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-123596",
    "datePublished": "2026-11-08T01:38:25.747Z",
    "dateReserved": "2026-11-06T01:00:16.505Z",
    "dateUpdated": "2026-11-08T01:38:25.747Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}