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CVE-2026-56820

Estado: AnalizadaCrítica (9.1)—

Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and prior to 4.1.135.Final, `OcspClient` does not validate that the `CertificateID` in an OCSP response matches the requested `CertificateID`, which can lead to replay attack. `OcspClient.validateResponse` accepts a legitimately signed `GOOD` status response for an unrelated certificate issued by the same CA, allowing bypass of revocation checks for another certificate. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

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 validación en OCSP (CWE-295) explotable remotamente sin autenticación (AV:N/PR:N/UI:N). El bypass de revocation checks mediante respuesta OCSP falsificada permite Man-in-the-Middle y acceso a credenciales de certificados.

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

Network SegmentationLimit Access to Resource Over NetworkFilter Network TrafficVulnerability ScanningUser TrainingPrivileged Account Management

Tecnologías afectadas (1)

Netty — Netty

CWE

Referencias

JSON original (NVD)

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          "version": "2.0.3",
          "timestamp": "2026-07-24T03:55:59.408001Z"
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  "lastModified": "2026-07-30T14:48:49.323",
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