CASCACascade Atlas

Evidence dossier

CVE-2025-21333

Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability

Exploited in the wild (CISA KEV since Jan 14, 2025). microsoft reports CVSS 3.1 7.8. EPSS estimates 10.0% exploit likelihood as of Aug 27, 2026.

71.5–75.9Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability

State
PUBLISHED
Published
Jan 14, 2025
Updated
Jun 9, 2026
Evidence coverage
91%

Evidence chronology

What was known when

Download this view's receipt →
  1. Source dateSource date omittedFirst observed by CASCA
    CISA-ADP

    Record text: CISA ADP Vulnrichment

    Inspect raw assertion
    Field
    container
    Value
    CISA ADP Vulnrichment
    Original evidence ↗
  2. Source dateSource date omittedFirst observed by CASCA
    CVE Program

    Record text: CVE Program Container

    Inspect raw assertion
    Field
    container
    Value
    CVE Program Container
    Original evidence ↗
  3. Source dateSource date omittedFirst observed by CASCA
    microsoft

    Record text: Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability

    Inspect raw assertion
    Field
    container
    Value
    Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 9.99% probability · 95.25th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.099880000000; percentile 0.952500000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Jan 14, 2025 · first observed Jul 19, 2026

Exploit likelihood9.99%

FIRST EPSS · score date Aug 27, 2026 · 95.3th percentile · first observed Aug 27, 2026

SeverityCVSS 7.8

microsoft · CVSS 3.1 · first observed Jul 19, 2026 · same-version scores align in this snapshot

Evidence detail

Source limits and decisions

Why each evidence state has this value

casca-unknown-reasons-v1
Exploitation statusEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Aug 27, 2026
Resolution
None
Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Aug 27, 2026
Resolution
None
Affected productsSource-reported scope

The cited source assertion is retained while canonical product linkage remains open.

Revision
casca-factor-d-obligations-v1
Cutoff
Aug 27, 2026
Resolution
Resolve identity

Source comparison

Who said what

CISA-ADPIndependent enrichment
Record text

CISA ADP Vulnrichment

Inspect raw assertion
Field
container
Value
CISA ADP Vulnrichment
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CVE ProgramDerivative copy
Record text

CVE Program Container

Inspect raw assertion
Field
container
Value
CVE Program Container
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
microsoftOriginal assertion
Record text

Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability

Inspect raw assertion
Field
container
Value
Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

9.99% probability · 95.25th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.099880000000; percentile 0.952500000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
7Underlying assertions
7Canonical products
7Target assertions
0Constraint assertions

Grouped from 1 configuration nodes in this exact snapshot. Visual grouping is navigational; asset exposure and root cause require cited evidence.

Identity source boundaries
  • Cpe dictionary1,775,266 records · observed through 2026-07-21T06:45:29.809Z27d65b0f-b718-4b4f-bb79-c47c68d09dfa
  • Cpe match643,502 records · observed through 2026-07-21T08:13:17.697Z955dae73-7302-438b-aee1-058d7cc5d48e

16 scope groups

microsoft · source assertedMicrosoftWindows 10 Version 21H2Direct source scope
Affected: 10.0.19044.0 to before 10.0.19044.5371 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.19044.0", "lessThan": "10.0.19044.5371", "versionType": "custom"}]
microsoft · source assertedMicrosoftWindows 10 Version 22H2Direct source scope
Affected: 10.0.19045.0 to before 10.0.19045.5371 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.19045.0", "lessThan": "10.0.19045.5371", "versionType": "custom"}]
microsoft · source assertedMicrosoftWindows 11 version 22H2Direct source scope
Affected: 10.0.22621.0 to before 10.0.22621.4751 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.22621.0", "lessThan": "10.0.22621.4751", "versionType": "custom"}]
microsoft · source assertedMicrosoftWindows 11 version 22H3Direct source scope
Affected: 10.0.22631.0 to before 10.0.22631.4751 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.22631.0", "lessThan": "10.0.22631.4751", "versionType": "custom"}]
microsoft · source assertedMicrosoftWindows 11 Version 23H2Direct source scope
Affected: 10.0.22631.0 to before 10.0.22631.4751 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.22631.0", "lessThan": "10.0.22631.4751", "versionType": "custom"}]
microsoft · source assertedMicrosoftWindows 11 Version 24H2Direct source scope
Affected: 10.0.26100.0 to before 10.0.26100.2894 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.2894", "versionType": "custom"}]
microsoft · source assertedMicrosoftWindows Server 2022, 23H2 Edition (Server Core installation)Direct source scope
Affected: 10.0.25398.0 to before 10.0.25398.1369 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.25398.0", "lessThan": "10.0.25398.1369", "versionType": "custom"}]
microsoft · source assertedMicrosoftWindows Server 2025Direct source scope
Affected: 10.0.26100.0 to before 10.0.26100.2894 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.2894", "versionType": "custom"}]
microsoft · source assertedMicrosoftWindows Server 2025 (Server Core installation)Direct source scope
Affected: 10.0.26100.0 to before 10.0.26100.2894 (custom comparison)
Source-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Inspect raw assertion[{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.2894", "versionType": "custom"}]
NVD CPE · OPERATING SYSTEMmicrosoftwindows_10_21h2Vulnerable target · 1 assertions
Any version (unconstrained) (< 10.0.19044.5371)Canonical identity product-ec10c9f400f23fdf118887f60fe116ffde4adb76dcf118cdd3a7556fd033da3bLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    through excluding 10.0.19044.5371
    Match ID
    c4af6108-e473-4695-b5ae-a4449a7a6e22
NVD CPE · OPERATING SYSTEMmicrosoftwindows_10_22h2Vulnerable target · 1 assertions
Any version (unconstrained) (< 10.0.19045.5371)Canonical identity product-a6295b9daad3ca57ce70751badba5b7fe99229c8a562cc7400e8cfef3daccaeeLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    through excluding 10.0.19045.5371
    Match ID
    146c68db-cb79-4cca-bccf-ddb7e6b543dc
NVD CPE · OPERATING SYSTEMmicrosoftwindows_11_22h2Vulnerable target · 1 assertions
Any version (unconstrained) (< 10.0.22621.4751)Canonical identity product-f8c509b6ec25f2a4338a23556be321da5a7c3e8da9f1a4c52f7f15dd0e9a0d2aLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_11_22h2:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 2
    Logic
    OR
    Version bounds
    through excluding 10.0.22621.4751
    Match ID
    d84edf98-16e1-412a-9879-2c2fef87fb2b
NVD CPE · OPERATING SYSTEMmicrosoftwindows_11_23h2Vulnerable target · 1 assertions
Any version (unconstrained) (< 10.0.22631.4751)Canonical identity product-026201767813843a6d53867bacde4a55c3035cb868c0a72434012c5e30dab148Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 3
    Logic
    OR
    Version bounds
    through excluding 10.0.22631.4751
    Match ID
    282e3839-e953-4b14-a860-dbacc1e99aff
NVD CPE · OPERATING SYSTEMmicrosoftwindows_11_24h2Vulnerable target · 1 assertions
Any version (unconstrained) (< 10.0.26100.2894)Canonical identity product-8665879a2f5fe8b8eab868c43d6ace340b95d1f3879639d97ebdf60ef7b49b5fLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 4
    Logic
    OR
    Version bounds
    through excluding 10.0.26100.2894
    Match ID
    78a3f671-95dc-442a-a511-1e875df93546
NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_2022_23h2Vulnerable target · 1 assertions
Any version (unconstrained) (< 10.0.25398.1369)Canonical identity product-bc66b50eed682b3633d0f3a2914725d0a72d6d0d5fece14f566d91bc87448c0bLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:x64:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 5
    Logic
    OR
    Version bounds
    through excluding 10.0.25398.1369
    Match ID
    b315e632-8658-4cd5-972b-892c1cc738a3
NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_2025Vulnerable target · 1 assertions
Any version (unconstrained) (< 10.0.26100.2894)Canonical identity product-3fe7da0d567cbba9da3f09deea827ccacd90ac3643fc3e1622f75fb001f24443Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 6
    Logic
    OR
    Version bounds
    through excluding 10.0.26100.2894
    Match ID
    2cfd18d5-3c1f-4e3a-a143-ee3f1ffbb880

Affected-product evidence

Accepted scope and product mapping

7 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-026201767813843a6d53867bacde4a55c3035cb868c0a72434012c5e30dab148

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
d1d67855-bb59-4d96-88f4-f470b84688ae
Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-3fe7da0d567cbba9da3f09deea827ccacd90ac3643fc3e1622f75fb001f24443

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
31f98ea5-d221-43a7-b73c-e58e407c441a
Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-8665879a2f5fe8b8eab868c43d6ace340b95d1f3879639d97ebdf60ef7b49b5f

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
3b23636f-24ff-45a6-9f2e-11929ba8573a
Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-a6295b9daad3ca57ce70751badba5b7fe99229c8a562cc7400e8cfef3daccaee

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
fca3c21a-b01d-4f25-a4dc-b07bc769e2c3
Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-bc66b50eed682b3633d0f3a2914725d0a72d6d0d5fece14f566d91bc87448c0b

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
ecc4aca7-c05b-42af-817e-10b6ef269d0e
Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-ec10c9f400f23fdf118887f60fe116ffde4adb76dcf118cdd3a7556fd033da3b

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
1450a67c-65b2-4d12-af3b-1748e35d58d3
Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-f8c509b6ec25f2a4338a23556be321da5a7c3e8da9f1a4c52f7f15dd0e9a0d2a

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
f7050dcd-eaa7-44d4-a557-3508339163fa
Source-reported scopeSource-reported scope

Canonical linkage remains open; the cited source assertion is retained below.

Vendor specified only by source · Product specified only by source

Source class
Direct cve affected
Assertions
9
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
104abc8d-83e7-4749-bdf5-fe1012c75758172dc988-8694-4093-bb79-6d26ea874a7533d49295-540a-47dc-8033-5b546288ce313c767024-0728-4417-9e8e-64af6297c6747265c88a-f946-42e9-b1d4-765cbfb5e3497d779fea-27ec-4b2d-9dde-e7fcd67940ffaaa09e42-5a55-4c29-9d50-a936b9344d7cdbd09d96-add9-4caf-98c1-f04f91280fd1eaa275b0-ec30-4a2b-a36f-ed66e7f7fd69

Assessments

CVSS by origin

7.8
secure@microsoft.comCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8
microsoftCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Direct CVE/CNA normalized decisions

7.8Priority eligible

microsoft

CVSS 3.1 · Primary · Original assertion · rank 1

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
Validation
Valid match
Recomputed
7.8
Decision reason
Evidence supported
Policy
casca-direct-cvss-eligibility-v1

Assessments are retained side by side under closed precedence. Cascade never averages CVSS.

Evidence boundaries

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; remaining scope stays source-scoped.
  • NVD-carried upstream facts remain derivative; independent corroboration requires a separately authored source.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.
  • OSV aggregation and OSV-converted NVD material are not independent corroboration.
  • Red Hat facts are vendor assertions for the exact supplied products.
  • Nonmembership and not-yet-observed states are not proof of safety.