Exploitation evidence
Known exploited · CISA KEV listed
Added 2025-01-14. Ransomware campaign use: Unknown.
CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
CISA due date: 2025-02-04. This is the catalog’s deadline, not an assessment of your organization’s exposure.
KEV checked 13 Nov 2026, 00:20 Jerusalem · Original catalog ↗Reported products and versions
Microsoft / Windows 10 Version 21H2
Default status: Not specified
- affected: 10.0.19044.0 to < 10.0.19044.5371 (custom)
Microsoft / Windows 10 Version 22H2
Default status: Not specified
- affected: 10.0.19045.0 to < 10.0.19045.5371 (custom)
Microsoft / Windows 11 version 22H2
Default status: Not specified
- affected: 10.0.22621.0 to < 10.0.22621.4751 (custom)
Microsoft / Windows 11 version 22H3
Default status: Not specified
- affected: 10.0.22631.0 to < 10.0.22631.4751 (custom)
Microsoft / Windows 11 Version 23H2
Default status: Not specified
- affected: 10.0.22631.0 to < 10.0.22631.4751 (custom)
Microsoft / Windows 11 Version 24H2
Default status: Not specified
- affected: 10.0.26100.0 to < 10.0.26100.2894 (custom)
Microsoft / Windows Server 2022, 23H2 Edition (Server Core installation)
Default status: Not specified
- affected: 10.0.25398.0 to < 10.0.25398.1369 (custom)
Microsoft / Windows Server 2025
Default status: Not specified
- affected: 10.0.26100.0 to < 10.0.26100.2894 (custom)
Microsoft / Windows Server 2025 (Server Core installation)
Default status: Not specified
- affected: 10.0.26100.0 to < 10.0.26100.2894 (custom)
Fixes and workarounds
No explicit solution text in the downloaded CVE record. Consult the vendor advisory; unaffected version ranges are shown above as reported, not inferred as a patch recommendation.
Sources and related reporting
CVE Program record ↗ · Download tracked evidence as JSON
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21333
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21333
- https://www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-mitigation-script
- https://www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-detection-script
- https://www.exploit-db.com/exploits/52436
Observed change timeline
History begins when Egret first downloads each source. It is not the complete upstream CVE history.
12 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-12",
"epss": 0.10066,
"percentile": 0.95692
}10 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-10",
"epss": 0.10066,
"percentile": 0.95664
}09 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-09",
"epss": 0.10066,
"percentile": 0.9566
}08 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-08",
"epss": 0.10066,
"percentile": 0.95659
}07 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-07",
"epss": 0.10066,
"percentile": 0.95656
}06 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-06",
"epss": 0.10066,
"percentile": 0.9565
}06 Nov 2026, 06:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-05",
"epss": 0.10066,
"percentile": 0.95645
}04 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-04",
"epss": 0.10066,
"percentile": 0.95642
}04 Nov 2026, 00:20 Jerusalem · CVE Program record changed
Stored CNA snapshot at this observation.
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"dateAdded": "2025-01-14",
"reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21333"
},
"type": "kev"
}
},
{
"other": {
"content": {
"id": "CVE-2025-21333",
"options": [
{
"Exploitation": "active"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"timestamp": "2025-01-23T04:55:45.770568Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-02-26T19:09:10.751Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"tags": [
"government-resource"
],
"url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21333"
}
],
"timeline": [
{
"lang": "en",
"time": "2025-01-14T00:00:00.000Z",
"value": "CVE-2025-21333 added to CISA KEV"
}
],
"title": "CISA ADP Vulnrichment"
},
{
"providerMetadata": {
"dateUpdated": "2025-10-31T14:58:09.208Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"url": "https://www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-mitigation-script"
},
{
"url": "https://www.vicarius.io/vsociety/posts/cve-2025-21333-elevated-privilege-exposure-in-windows-hyper-v-by-microsoft-detection-script"
},
{
"url": "https://www.exploit-db.com/exploits/52436"
}
],
"title": "CVE Program Container",
"x_generator": {
"engine": "ADPogram 0.0.1"
}
}
],
"cna": {
"affected": [
{
"platforms": [
"x64-based Systems"
],
"product": "Windows 10 Version 21H2",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.19044.5371",
"status": "affected",
"version": "10.0.19044.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows 10 Version 22H2",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.19045.5371",
"status": "affected",
"version": "10.0.19045.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"ARM64-based Systems",
"x64-based Systems"
],
"product": "Windows 11 version 22H2",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.22621.4751",
"status": "affected",
"version": "10.0.22621.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"ARM64-based Systems"
],
"product": "Windows 11 version 22H3",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.22631.4751",
"status": "affected",
"version": "10.0.22631.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows 11 Version 23H2",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.22631.4751",
"status": "affected",
"version": "10.0.22631.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"ARM64-based Systems",
"x64-based Systems"
],
"product": "Windows 11 Version 24H2",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.26100.2894",
"status": "affected",
"version": "10.0.26100.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows Server 2022, 23H2 Edition (Server Core installation)",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.25398.1369",
"status": "affected",
"version": "10.0.25398.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows Server 2025",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.26100.2894",
"status": "affected",
"version": "10.0.26100.0",
"versionType": "custom"
}
]
},
{
"platforms": [
"x64-based Systems"
],
"product": "Windows Server 2025 (Server Core installation)",
"vendor": "Microsoft",
"versions": [
{
"lessThan": "10.0.26100.2894",
"status": "affected",
"version": "10.0.26100.0",
"versionType": "custom"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:microsoft:windows_10_21H2:*:*:*:*:*:*:x64:*",
"versionEndExcluding": "10.0.19044.5371",
"versionStartIncluding": "10.0.19044.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_11_22H2:*:*:*:*:*:*:arm64:*",
"versionEndExcluding": "10.0.22621.4751",
"versionStartIncluding": "10.0.22621.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_10_22H2:*:*:*:*:*:*:x64:*",
"versionEndExcluding": "10.0.19045.5371",
"versionStartIncluding": "10.0.19045.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*",
"versionEndExcluding": "10.0.26100.2894",
"versionStartIncluding": "10.0.26100.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_11_23H2:*:*:*:*:*:*:arm64:*",
"versionEndExcluding": "10.0.22631.4751",
"versionStartIncluding": "10.0.22631.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_11_23H2:*:*:*:*:*:*:x64:*",
"versionEndExcluding": "10.0.22631.4751",
"versionStartIncluding": "10.0.22631.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_23h2:*:*:*:*:*:*:*:*",
"versionEndExcluding": "10.0.25398.1369",
"versionStartIncluding": "10.0.25398.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_11_24H2:*:*:*:*:*:*:arm64:*",
"versionEndExcluding": "10.0.26100.2894",
"versionStartIncluding": "10.0.26100.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*",
"versionEndExcluding": "10.0.26100.2894",
"versionStartIncluding": "10.0.26100.0",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"datePublic": "2025-01-14T08:00:00.000Z",
"descriptions": [
{
"lang": "en-US",
"value": "Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability"
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C",
"version": "3.1"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en-US",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-122",
"description": "CWE-122: Heap-based Buffer Overflow",
"lang": "en-US",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-06-09T18:30:14.696Z",
"orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8",
"shortName": "microsoft"
},
"references": [
{
"name": "Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability",
"tags": [
"vendor-advisory",
"patch"
],
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21333"
}
],
"title": "Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability"
}
},
"cveMetadata": {
"assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8",
"assignerShortName": "microsoft",
"cveId": "CVE-2025-21333",
"datePublished": "2025-01-14T18:04:50.962Z",
"dateReserved": "2024-12-11T00:29:48.351Z",
"dateUpdated": "2026-06-09T18:30:14.696Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}03 Nov 2026, 18:20 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-03",
"epss": 0.10066,
"percentile": 0.95634
}03 Nov 2026, 02:22 Jerusalem · EPSS observation updated
Stored EPSS snapshot at this observation.
{
"date": "2026-11-02",
"epss": 0.10066,
"percentile": 0.95628
}03 Nov 2026, 02:22 Jerusalem · CISA KEV status changed
Stored KEV snapshot at this observation.
{
"cveID": "CVE-2025-21333",
"cwes": [
"CWE-122"
],
"dateAdded": "2025-01-14",
"dueDate": "2025-02-04",
"forensicTriage": "No",
"knownRansomwareCampaignUse": "Unknown",
"notes": "https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2025-21333 ; https://nvd.nist.gov/vuln/detail/CVE-2025-21333",
"product": "Windows",
"requiredAction": "Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.",
"shortDescription": "Microsoft Windows Hyper-V NT Kernel Integration VSP contains a heap-based buffer overflow vulnerability that allows a local attacker to gain SYSTEM privileges.",
"vendorProject": "Microsoft",
"vulnerabilityName": "Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow Vulnerability"
}