CVE-2026-123586

Description

Hickory DNS 0.25.0-alpha.3 through 0.25.2 contains a query amplification vulnerability in its recursive resolver, which mishandles cyclic sibling name server referrals that lack glue records. Attackers controlling two zones whose name servers reference each other without glue records can make the recursor loop, sending many upstream queries, amplified further by zero-TTL NS records.

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:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Effective score: 8.7 / 10 HIGH source: CNA overview
CWE(s): CWE-400
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-2026-123586.json
Linked Threat: CVE-2026-123586 — Hickory DNS 0.25.0-alpha.3 through 0.25.2 Query Amplification via Cyclic Referrals

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-2026-119345

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

Affected products (2)

Vendor	Product	Versions	Platforms
hickory-dns	hickory-dns	`0.25.0-alpha.3` (affected)	—
hickory-dns	hickory-dns	`0` (affected), `0.26.2` (unaffected)	—

Vendor references (2)

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

GitHub Security Advisory (GHSA-cx5j-p54p-q756) vendor-advisory
VulnCheck Advisory: Hickory DNS 0.25.0-alpha.3 through 0.25.2 Query Amplification via Cyclic Referrals 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.

October 2026 Critical Patch Update Released | security

web:blogs.oracle.com

For more information about the Critical Patch Update program, see the security vulnerability remediation practices page located on the Oracle Trust Center.

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
sshole (CVE-2026-123158): OpenSSH Auth Bypass on Alpine | Cycode

web:cycode.com

Learn about sshole ( CVE - 2026 -123158), an OpenSSH authentication bypass vulnerability affecting Alpine Linux, key exposure criteria, affected public images, and fix guidance.

2026-11-08 10:22 UTC
Microsoft Patch Tracker (November 2026): Exploit-Ranked | Senserva

web:senserva.com

Every Microsoft security patch (KB) and the CVEs it fixes, with severity, CVSS, and CISA KEV status. Cross-linked to the CVE reference.

2026-11-08 10:22 UTC
SAP Security Patch Day - October 2026

web:support.sap.com

On 13 th of October 2026 , SAP security patch day saw the release of 16 new security notes and 4 GitHub security advisories. There are 2 updates to previously released security notes.

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
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
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
Oracle Critical Security Patch Update Advisory - September 2026

web:www.oracle.com

Prior Critical Patch Update and Critical Security Patch Update advisories should be reviewed for information regarding earlier published security patches. Refer to Critical Patch Updates, Critical Security Patch Updates, Security Alerts and Bulletins for information about Oracle Security advisories.

2026-11-08 10:22 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-123586.json.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:cargo/hickory-recursor",
          "product": "hickory-dns",
          "vendor": "hickory-dns",
          "versions": [
            {
              "lessThanOrEqual": "0.25.2",
              "status": "affected",
              "version": "0.25.0-alpha.3",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:cargo/hickory-resolver",
          "product": "hickory-dns",
          "vendor": "hickory-dns",
          "versions": [
            {
              "lessThan": "0.26.2",
              "status": "affected",
              "version": "0",
              "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",
          "value": "Hickory DNS 0.25.0-alpha.3 through 0.25.2 contains a query amplification vulnerability in its recursive resolver, which mishandles cyclic sibling name server referrals that lack glue records. Attackers controlling two zones whose name servers reference each other without glue records can make the recursor loop, sending many upstream queries, amplified further by zero-TTL NS records."
        }
      ],
      "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": "NONE",
            "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:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS"
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-400",
              "description": "Uncontrolled Resource Consumption",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-08T01:38:18.937Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "GitHub Security Advisory (GHSA-cx5j-p54p-q756)",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-cx5j-p54p-q756"
        },
        {
          "name": "VulnCheck Advisory: Hickory DNS 0.25.0-alpha.3 through 0.25.2 Query Amplification via Cyclic Referrals",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/hickory-dns-0.25.0-alpha.3-through-0.25.2-query-amplification-via-cyclic-referrals"
        }
      ],
      "title": "Hickory DNS 0.25.0-alpha.3 through 0.25.2 Query Amplification via Cyclic Referrals",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-123586",
    "datePublished": "2026-11-08T01:38:18.937Z",
    "dateReserved": "2026-11-06T00:57:31.044Z",
    "dateUpdated": "2026-11-08T01:38:18.937Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}