CVE-2026-40366
Full vulnerability record from the local CVENow database.
Description
Access of resource using incompatible type ('type confusion') in Microsoft Office Word allows an unauthorized attacker to execute code locally.
Severity
HIGH
CVSS score
8.4
(v3.1)
Vulnerability status
Modified
Source identifier
Published
2026-05-12 18:17:15.610000
Last modified
2026-10-26 18:10:00.173000
View original CVE JSON
{
"id": "CVE-2026-40366",
"sourceIdentifier": "[email protected]",
"published": "2026-05-12T18:17:15.610",
"lastModified": "2026-10-26T18:10:00.173",
"vulnStatus": "Modified",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Access of resource using incompatible type ('type confusion') in Microsoft Office Word allows an unauthorized attacker to execute code locally."
},
{
"lang": "es",
"value": "Acceso de recurso usando un tipo incompatible (’confusión de tipos’) en Microsoft Office Word permite a un atacante no autorizado ejecutar código localmente."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "Microsoft",
"product": "Microsoft 365 Apps for Enterprise",
"platforms": [
"32-bit Systems",
"x64-based Systems"
],
"versions": [
{
"version": "16.0.1",
"lessThan": "https://aka.ms/OfficeSecurityReleases",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Microsoft",
"product": "Microsoft Office 2019",
"platforms": [
"32-bit Systems",
"x64-based Systems"
],
"versions": [
{
"version": "19.0.0",
"lessThan": "https://aka.ms/OfficeSecurityReleases",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Microsoft",
"product": "Microsoft Office LTSC 2021",
"platforms": [
"32-bit Systems",
"x64-based Systems"
],
"versions": [
{
"version": "16.0.1",
"lessThan": "https://aka.ms/OfficeSecurityReleases",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Microsoft",
"product": "Microsoft Office LTSC 2024",
"platforms": [
"32-bit Systems",
"x64-based Systems"
],
"versions": [
{
"version": "16.0.0",
"lessThan": "https://aka.ms/OfficeSecurityReleases",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Microsoft",
"product": "Microsoft Office LTSC for Mac 2021",
"versions": [
{
"version": "16.0.1",
"lessThan": "16.109.26051019",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Microsoft",
"product": "Microsoft Office LTSC for Mac 2024",
"versions": [
{
"version": "16.0.0",
"lessThan": "16.109.26051019",
"versionType": "custom",
"status": "affected"
}
]
},
{
"vendor": "Microsoft",
"product": "Microsoft Word 2016",
"platforms": [
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],
"versions": [
{
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"lessThan": "16.0.5552.1000",
"versionType": "custom",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 8.4,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 2.5,
"impactScore": 5.9
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-05-13T03:57:28.439839Z",
"id": "CVE-2026-40366",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-416"
}
]
}
],
"configurations": [
{
"nodes": [
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"negate": false,
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{
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}
],
"references": [
{
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40366",
"source": "[email protected]",
"tags": [
"Vendor Advisory"
]
}
]
}