CVE-2026-63940

Estado: Pendiente de análisisCrítica (9.3)—

In the Linux kernel, the following vulnerability has been resolved:

KVM: SEV: Ignore Port I/O requests of length '0'

Explicitly ignore Port I/O requests of length '0' (or count '0'), so that setting up the software scratch area (and other code) doesn't have to worry about underflowing the length, and to allow for WARNing on trying to configure the scratch area with len==0.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Puntuación base: 9.3

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.20%
Percentil entre todas las CVEs puntuadas: 8
Fecha de la puntuación: 6/10/2026

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.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation90 %

CVE en Linux kernel (AV:L, PR:N, UI:N) permite escalada de privilegios. Acceso local sin interacción: T1068. Impactos: ejecución de código arbitraria (C:H, I:H) y potencial DoS (A:H) en máquinas virtuales KVM/SEV.

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

Threat Intelligence Program Execution Prevention Application Isolation and Sandboxing Exploit Protection Update Software

Tecnologías afectadas (1)

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

Linux — Linux Kernel^AI

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-63940",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 9.3,
          "attackVector": "LOCAL",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 6,
        "exploitabilityScore": 2.5
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "291bd20d5d88814a73d43b55b9428feab2f28094",
              "lessThan": "3b6035bc6bff20e89752ce4358bc4c9a9d5883f2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "291bd20d5d88814a73d43b55b9428feab2f28094",
              "lessThan": "2254972d4d69e279ba4e87bf0968eb08ad0d3c92",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "291bd20d5d88814a73d43b55b9428feab2f28094",
              "lessThan": "c30cde934c7813b4e3069765dac64ce3d31e34f2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "291bd20d5d88814a73d43b55b9428feab2f28094",
              "lessThan": "3988bd2723de407ae90fa7a6f6029b4e60238c58",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "arch/x86/kvm/svm/sev.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.11"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.11",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.12.95",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.35",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.0.12",
              "versionType": "semver",
              "lessThanOrEqual": "7.0.*"
            },
            {
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "arch/x86/kvm/svm/sev.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-07-19T16:17:12.540",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/2254972d4d69e279ba4e87bf0968eb08ad0d3c92",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3988bd2723de407ae90fa7a6f6029b4e60238c58",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3b6035bc6bff20e89752ce4358bc4c9a9d5883f2",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c30cde934c7813b4e3069765dac64ce3d31e34f2",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Awaiting Analysis",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Ignore Port I/O requests of length '0'\n\nExplicitly ignore Port I/O requests of length '0' (or count '0'), so that\nsetting up the software scratch area (and other code) doesn't have to\nworry about underflowing the length, and to allow for WARNing on trying\nto configure the scratch area with len==0."
    }
  ],
  "lastModified": "2026-07-27T17:44:23.777",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}