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CVE-2026-2636

Estado: AplazadaMedia (5.5)—

This vulnerability is caused by a CWE‑159: "Improper Handling of Invalid Use of Special Elements" weakness, which leads to an unrecoverable inconsistency in the CLFS.sys driver. This condition forces a call to the KeBugCheckEx function, allowing an unprivileged user to trigger a system crash. Microsoft silently fixed this vulnerability in the September 2025 cumulative update for Windows 11 2024 LTSC and Windows Server 2025. Windows 25H2 (released in September) was released with the patch. Windows 1123h2 and earlier versions remain vulnerable.

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).

Tecnologías afectadas (3)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Microsoft — Windows 11AIMicrosoft — Windows 25h2AIMicrosoft — Windows Server 2025AI

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-2636",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-2636",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-02-26T15:56:12.707562Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "df4dee71-de3a-4139-9588-11b62fe6c0ff",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.5,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "affected": [
    {
      "source": "df4dee71-de3a-4139-9588-11b62fe6c0ff",
      "affectedData": [
        {
          "vendor": "Microsoft",
          "product": "Windows OS",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "lessThan": "25H2",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "0",
              "versionType": "semver",
              "lessThanOrEqual": "1123h2"
            }
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-02-25T20:23:48.910",
  "references": [
    {
      "url": "https://www.fortra.com/security/advisories/research/fr-2026-001",
      "source": "df4dee71-de3a-4139-9588-11b62fe6c0ff"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "df4dee71-de3a-4139-9588-11b62fe6c0ff",
      "description": [
        {
          "lang": "en",
          "value": "CWE-159"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "This vulnerability is caused by a CWE‑159: \"Improper Handling of Invalid Use of Special Elements\" weakness, which leads to an unrecoverable inconsistency in the CLFS.sys driver. This condition forces a call to the KeBugCheckEx function, allowing an unprivileged user to trigger a system crash. Microsoft silently fixed this vulnerability in the September 2025 cumulative update for Windows 11 2024 LTSC and Windows Server 2025. Windows 25H2 (released in September) was released with the patch. Windows 1123h2 and earlier versions remain vulnerable."
    },
    {
      "lang": "es",
      "value": "Esta vulnerabilidad se produce por un fallo CWE?159: 'Manejo Inadecuado del Uso Inválido de Elementos Especiales', lo que lleva a una inconsistencia irrecuperable en el controlador CLFS.sys. Esta condición fuerza una llamada a la función KeBugCheckEx, permitiendo a un usuario sin privilegios provocar un fallo del sistema. Microsoft corrigió silenciosamente esta vulnerabilidad en la actualización acumulativa de septiembre de 2025 para Windows 11 2024 LTSC y Windows Server 2025. Windows 25H2 (lanzado en septiembre) fue lanzado con el parche. Windows 1123h2 y versiones anteriores siguen siendo vulnerables."
    }
  ],
  "lastModified": "2026-06-17T10:31:26.537",
  "sourceIdentifier": "df4dee71-de3a-4139-9588-11b62fe6c0ff"
}