« Volver al listado

CVE-2026-56821

Estado: AnalizadaAlta (7.4)—

Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, the OcspServerCertificateValidator flags an out-of-date OCSP response but does not stop processing it, so an expired GOOD response is still reported as VALID, letting an on-path attacker replay a stale GOOD response to bypass revocation of a since-revoked certificate. Exploitation can lead to certificate revocation bypass via replay of an expired OCSP response. Any application using OcspServerCertificateValidator is affected; a revoked certificate can be accepted. This issue has been 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.

AV:N sin PR ni UI indica acceso remoto sin privilegios (T1190). El atacante en la ruta (on-path) replaya respuestas OCSP expiradas para eludir revocación (T1557: man-in-the-middle). Impacto secundario: manipulación de identidad de certificados (T1578).

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 TrainingUser Account Management

Tecnologías afectadas (1)

Netty — Netty

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-56821",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-56821",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-07-30T03:55:19.093244Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.4,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.2,
        "exploitabilityScore": 2.2
      }
    ]
  },
  "affected": [
    {
      "source": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "netty",
          "product": "netty",
          "versions": [
            {
              "status": "affected",
              "version": "< 4.1.136.Final"
            },
            {
              "status": "affected",
              "version": ">= 4.2.0.Final, < 4.2.16.Final"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-07-29T00:16:38.573",
  "references": [
    {
      "url": "https://github.com/netty/netty/security/advisories/GHSA-g7hg-vrcf-mvmr",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/netty/netty/security/advisories/GHSA-g7hg-vrcf-mvmr",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-299"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, the OcspServerCertificateValidator flags an out-of-date OCSP response but does not stop processing it, so an expired GOOD response is still reported as VALID, letting an on-path attacker replay a stale GOOD response to bypass revocation of a since-revoked certificate. Exploitation can lead to certificate revocation bypass via replay of an expired OCSP response. Any application using OcspServerCertificateValidator is affected; a revoked certificate can be accepted. This issue has been fixed in versions 4.1.136.Final and 4.2.16.Final."
    }
  ],
  "lastModified": "2026-08-07T15:05:53.920",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "3A15093F-C6A7-4FCF-81BA-939CD522D1DD",
              "versionEndExcluding": "4.1.136"
            },
            {
              "criteria": "cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "4DE4BC35-4405-49B5-A2A8-A700C7F63C8B",
              "versionEndExcluding": "4.2.16",
              "versionStartIncluding": "4.2.0"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "security-advisories@github.com"
}