CVE-2026-85887

Estado: AnalizadaAlta (7.7)—

Incorrect permission assignment for critical resource in M365 Copilot allows an authorized attacker to disclose information over a network.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
Puntuación base: 7.7

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.84%
Percentil entre todas las CVEs puntuadas: 56
Fecha de la puntuación: 5/10/2026

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.

ExplotaciónT1210 Exploitation of Remote Serviceslateral movement75 %
Impacto principalT1222 File and Directory Permissions Modificationdefense impairment80 %
Impacto secundarioT1005 Data from Local Systemcollection70 %

AV:N/PR:L sin UI indica explotación remota por usuario autenticado (T1210). CWE-732 (permisos incorrectos) y confidencialidad alta permiten acceso a recursos críticos con divulgación de información (T1222, T1005).

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 Management Vulnerability Scanning Threat Intelligence Program Restrict File and Directory Permissions Network Segmentation Disable or Remove Feature or Program

Tecnologías afectadas (1)

Microsoft — 365 Copilot

CWE

CWE-732

Referencias

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85887

JSON original (NVD)

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      "sourceIdentifier": "secure@microsoft.com"
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          "role": "CISA Coordinator",
          "options": [
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            },
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            },
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            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-09-18T13:35:20.282568Z"
        }
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          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 4,
        "exploitabilityScore": 3.1
      }
    ]
  },
  "affected": [
    {
      "source": "secure@microsoft.com",
      "affectedData": [
        {
          "vendor": "Microsoft",
          "product": "Microsoft 365 Copilot",
          "versions": [
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              "status": "affected",
              "version": "-"
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  "published": "2026-09-18T00:17:47.920",
  "references": [
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      "tags": [
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  ],
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    }
  ],
  "lastModified": "2026-09-28T18:37:31.143",
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}