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CVE-2026-19538

Estado: AnalizadaAlta (8.2)—

The BLOCKED access control list items that are evaluated to deny access on the the proxy protocol port can be bypassed completely when connecting over TCP or TLS and sending the query twice on connection that is kept open.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Vulnerabilidad de ACL burlable remotamente sin autenticación (AV:N, PR:N) en proxy protocol de NSD. Permite eludir controles de acceso reenviando consultas en conexión persistente.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Privileged Account ManagementApplication Developer GuidanceActive Directory ConfigurationVulnerability ScanningUser TrainingUser Account Management

Tecnologías afectadas (1)

Nlnetlabs — NSD

CWE

Referencias

JSON original (NVD)

Mostrar
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  "id": "CVE-2026-19538",
  "cveTags": [],
  "metrics": {
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        "ssvcData": {
          "id": "CVE-2026-19538",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-08-26T13:51:21.490331Z"
        }
      }
    ],
    "cvssMetricV31": [
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          "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",
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        "cvssData": {
          "Safety": "NOT_DEFINED",
          "version": "4.0",
          "Recovery": "NOT_DEFINED",
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          "Automatable": "NOT_DEFINED",
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "valueDensity": "NOT_DEFINED",
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          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "vulnAvailabilityImpact": "NONE",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "subConfidentialityImpact": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "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"
        }
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  },
  "affected": [
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      "source": "sep@nlnetlabs.nl",
      "affectedData": [
        {
          "vendor": "NLnet Labs",
          "product": "NSD",
          "versions": [
            {
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              "version": "4.8.0",
              "lessThan": "4.15.1",
              "versionType": "semver"
            }
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  ],
  "published": "2026-08-26T09:16:46.057",
  "references": [
    {
      "url": "https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-19538.txt",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "sep@nlnetlabs.nl"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "sep@nlnetlabs.nl",
      "description": [
        {
          "lang": "en",
          "value": "CWE-290"
        },
        {
          "lang": "en",
          "value": "CWE-672"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "The BLOCKED access control list items that are evaluated to deny access on the the proxy protocol port can be bypassed completely when connecting over TCP or TLS and sending the query twice on connection that is kept open."
    }
  ],
  "lastModified": "2026-09-08T19:59:34.000",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
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}