CVE-2026-93657

Status: DeferredHigh (8.7)—

hickory-resolver versions before 0.26.2 fail to propagate bogus DNSSEC proof states through the Resolver::lookup() and Resolver::lookup_ip() APIs, allowing invalid records to be returned as successful results. Attackers controlling the answering zone or positioned on the network path can have forged DNS records accepted as validated, bypassing DNSSEC authentication checks.

CVSS

Version: 4.0
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Base score: 8.7

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.40%
Percentile among all scored CVEs: 32
Score date: 10/5/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1190 Exploit Public-Facing Applicationinitial access85 %
Primary impactT1553.006 Code Signing Policy Modificationdefense impairment90 %
Secondary impactT1557.002 ARP Cache Poisoningcredential access · collection75 %

Vulnerabilidad en validación DNSSEC de hickory-resolver expuesta en red (AV:N, sin autenticación). Permite inyectar registros DNS fraudulentos (T1553.006: subversión de confianza en certificados/validación). Atacante en ruta de red (T1557.002) puede explotar fallo de propagación de estados DNSSEC.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Privileged Account Management Limit Access to Resource Over Network Filter Network Traffic Vulnerability Scanning User Training Restrict Registry Permissions

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Hickory-resolver — Hickory-resolver^AI

CWEs

CWE-347

References

Raw JSON (NVD)

Show

{
  "id": "CVE-2026-93657",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-93657",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-09-21T16:28:49.154433Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "disclosure@vulncheck.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
    ],
    "cvssMetricV40": [
      {
        "type": "Secondary",
        "source": "disclosure@vulncheck.com",
        "cvssData": {
          "Safety": "NOT_DEFINED",
          "version": "4.0",
          "Recovery": "NOT_DEFINED",
          "baseScore": 8.7,
          "Automatable": "NOT_DEFINED",
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "exploitMaturity": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "NONE",
          "subIntegrityImpact": "NONE",
          "vulnIntegrityImpact": "HIGH",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "vulnAvailabilityImpact": "NONE",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "subConfidentialityImpact": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "confidentialityRequirement": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED"
        }
      }
    ]
  },
  "affected": [
    {
      "source": "disclosure@vulncheck.com",
      "affectedData": [
        {
          "repo": "https://github.com/hickory-dns/hickory-dns",
          "vendor": "hickory-dns",
          "product": "hickory-resolver",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "lessThan": "0.26.2",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "0.26.2",
              "versionType": "semver"
            }
          ],
          "packageURL": "pkg:cargo/hickory-resolver",
          "packageName": "hickory-resolver",
          "collectionURL": "https://crates.io",
          "defaultStatus": "unaffected"
        }
      ]
    }
  ],
  "published": "2026-09-18T15:17:22.190",
  "references": [
    {
      "url": "https://github.com/hickory-dns/hickory-dns",
      "source": "disclosure@vulncheck.com"
    },
    {
      "url": "https://github.com/hickory-dns/hickory-dns/commit/30720f4fb22e5556ecbf26d2c8274ea4a9fdd238",
      "source": "disclosure@vulncheck.com"
    },
    {
      "url": "https://github.com/hickory-dns/hickory-dns/pull/3871",
      "source": "disclosure@vulncheck.com"
    },
    {
      "url": "https://github.com/hickory-dns/hickory-dns/releases/tag/v0.26.2",
      "source": "disclosure@vulncheck.com"
    },
    {
      "url": "https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-5j98-2g5x-46v6",
      "source": "disclosure@vulncheck.com"
    },
    {
      "url": "https://www.vulncheck.com/advisories/hickory-resolver-before-0.26.2-dnssec-validation-bypass",
      "source": "disclosure@vulncheck.com"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "disclosure@vulncheck.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-347"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "hickory-resolver versions before 0.26.2 fail to propagate bogus DNSSEC proof states through the Resolver::lookup() and Resolver::lookup_ip() APIs, allowing invalid records to be returned as successful results. Attackers controlling the answering zone or positioned on the network path can have forged DNS records accepted as validated, bypassing DNSSEC authentication checks."
    }
  ],
  "lastModified": "2026-09-22T20:53:07.383",
  "sourceIdentifier": "disclosure@vulncheck.com"
}