CVE-2026-20943

Estado: AnalizadaAlta (7)—

Untrusted search path in Microsoft Office allows an unauthorized attacker to execute code locally.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Puntuación base: 7

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.66%
Percentil entre todas las CVEs puntuadas: 50
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.

ExplotaciónT1203 Exploitation for Client Executionexecution85 %
Impacto principalT1574.007 Path Interception by PATH Environment Variablestealth · execution80 %
Impacto secundarioT1059 Command and Scripting Interpreterexecution75 %

AV:L + UI:R indica ejecución en cliente (abrir archivo preparado); CWE-426 (untrusted search path) sugiere DLL hijacking (T1574.007); la cadena termina en ejecución arbitraria de código (T1059).

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

Execution Prevention Audit Restrict Web-Based Content Restrict File and Directory Permissions Privileged Account Management Limit Software Installation

Tecnologías afectadas (3)

Microsoft — Office Microsoft — Office Deployment Tool Microsoft — Sharepoint Server

CWE

CWE-426

Referencias

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20943

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-20943",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-20943",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-01-14T04:56:10.239259Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "secure@microsoft.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "REQUIRED",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 1
      }
    ]
  },
  "affected": [
    {
      "source": "secure@microsoft.com",
      "affectedData": [
        {
          "vendor": "Microsoft",
          "product": "Microsoft Office 2016",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.0",
              "lessThan": "16.0.5535.1000",
              "versionType": "custom"
            }
          ],
          "platforms": [
            "32-bit Systems",
            "x64-based Systems"
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft Office Deployment Tool",
          "versions": [
            {
              "status": "affected",
              "version": "1.0",
              "lessThan": "16.0.19426.20170",
              "versionType": "custom"
            }
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft SharePoint Enterprise Server 2016",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.0",
              "lessThan": "16.0.5535.1001",
              "versionType": "custom"
            }
          ],
          "platforms": [
            "x64-based Systems"
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft SharePoint Server 2019",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.0",
              "lessThan": "16.0.10417.20083",
              "versionType": "custom"
            }
          ],
          "platforms": [
            "x64-based Systems"
          ]
        },
        {
          "vendor": "Microsoft",
          "product": "Microsoft SharePoint Server Subscription Edition",
          "versions": [
            {
              "status": "affected",
              "version": "16.0.0",
              "lessThan": "16.0.19127.20442",
              "versionType": "custom"
            }
          ],
          "platforms": [
            "x64-based Systems"
          ]
        }
      ]
    }
  ],
  "published": "2026-01-13T18:16:21.687",
  "references": [
    {
      "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20943",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "secure@microsoft.com"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "secure@microsoft.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-426"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Untrusted search path in Microsoft Office allows an unauthorized attacker to execute code locally."
    },
    {
      "lang": "es",
      "value": "Ruta de búsqueda no confiable en Microsoft Office permite a un atacante no autorizado ejecutar código localmente."
    }
  ],
  "lastModified": "2026-06-17T10:18:05.373",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:x64:*",
              "vulnerable": true,
              "matchCriteriaId": "72324216-4EB3-4243-A007-FEF3133C7DF9"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:x86:*",
              "vulnerable": true,
              "matchCriteriaId": "0FBB0E61-7997-4F26-9C07-54912D3F1C10"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:office_deployment_tool:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "2D4CAEAF-A5AF-46D2-9A2B-8B04CC120B04",
              "versionEndExcluding": "16.0.19426.20170"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:sharepoint_server:*:*:*:*:subscription:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "FB9ECA81-C1E2-4B02-A45C-0E5664E3C9B9",
              "versionEndExcluding": "16.0.19127.20442"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:sharepoint_server:2016:*:*:*:enterprise:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F815EF1D-7B60-47BE-9AC2-2548F99F10E4"
            },
            {
              "criteria": "cpe:2.3:a:microsoft:sharepoint_server:2019:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "6122D014-5BF1-4AF4-8B4D-80205ED7785E"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "secure@microsoft.com"
}