Evidence dossier

CVE-2021-42278

Active Directory Domain Services Elevation of Privilege Vulnerability

Exploited in the wild (CISA KEV since Apr 11, 2022). microsoft reports CVSS 3.1 7.5. EPSS estimates 73.3% exploit likelihood as of Oct 22, 2026.

75.9–87.8Priority evidence range

Evidence through Oct 22, 2026, 6:07 PM UTC

As of Oct 22, 2026

Normalized restatement

Active Directory Domain Services Elevation of Privilege Vulnerability

State: PUBLISHED
Published: Nov 10, 2021
Updated: Aug 19, 2026
Evidence coverage: 85%

Evidence chronology

What was known when

Download this view's receipt →

Source dateSource date omittedFirst observed by CASCAAug 19, 2026
CISA-ADP
Record text: CISA ADP Vulnrichment
Inspect raw assertion
Field
container
Value
CISA ADP Vulnrichment
Original evidence ↗
Source dateSource date omittedFirst observed by CASCAAug 19, 2026
CVE Program
Record text: CVE Program Container
Inspect raw assertion
Field
container
Value
CVE Program Container
Original evidence ↗
Source dateSource date omittedFirst observed by CASCAAug 19, 2026
microsoft
Record text: Active Directory Domain Services Elevation of Privilege Vulnerability
Inspect raw assertion
Field
container
Value
Active Directory Domain Services Elevation of Privilege Vulnerability
Original evidence ↗
Source dateSep 1, 2026First observed by CASCASep 1, 2026
CISA KEV
Exploitation cataloged: Microsoft Active Directory Domain Services Privilege Escalation Vulnerability
Inspect raw assertion
Field
observed_exploitation
Value
Microsoft Active Directory Domain Services Privilege Escalation Vulnerability
Original evidence ↗
Source dateOct 22, 2026First observed by CASCAOct 22, 2026
FIRST EPSS
EPSS score: 73.3% probability · 99.46th percentile
Inspect raw assertion
Field
model_probability
Value
Probability 0.732970000000; percentile 0.994640000000
Original evidence ↗

ExploitationCatalog member

CISA KEV · catalog date Apr 11, 2022 · first observed Sep 1, 2026

Exploit likelihood73.30%

FIRST EPSS · score date Oct 22, 2026 · 99.5th percentile · first observed Oct 22, 2026

SeverityCVSS 7.5

microsoft · CVSS 3.1 · first observed Aug 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 statusLast verified source snapshot retained

The last verified source boundary remains in force for this claim.

Revision: evidence-policy-v1.1.0
Cutoff: Oct 22, 2026
Resolution: Review source contract

Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision: evidence-policy-v1.1.0
Cutoff: Oct 22, 2026
Resolution: None

Severity assessmentEvidence supported

Eligible evidence is present for this bounded claim.

Revision: casca-direct-cvss-eligibility-v1
Cutoff: Oct 22, 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: Oct 22, 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 CASCAAug 19, 2026Original evidence ↗

CVE ProgramDerivative copy

Record text

CVE Program Container

Inspect raw assertion

Field: container
Value: CVE Program Container

Source dateSource date omittedFirst observed by CASCAAug 19, 2026Original evidence ↗

microsoftOriginal assertion

Record text

Active Directory Domain Services Elevation of Privilege Vulnerability

Inspect raw assertion

Field: container
Value: Active Directory Domain Services Elevation of Privilege Vulnerability

Source dateSource date omittedFirst observed by CASCAAug 19, 2026Original evidence ↗

CISA KEVOriginal assertion

Exploitation cataloged

Microsoft Active Directory Domain Services Privilege Escalation Vulnerability

Inspect raw assertion

Field: observed_exploitation
Value: Microsoft Active Directory Domain Services Privilege Escalation Vulnerability

Source dateSep 1, 2026First observed by CASCASep 1, 2026Original evidence ↗

FIRST EPSSOriginal assertion

EPSS score

73.3% probability · 99.46th percentile

Inspect raw assertion

Field: model_probability
Value: Probability 0.732970000000; percentile 0.994640000000

Source dateOct 22, 2026First observed by CASCAOct 22, 2026Original evidence ↗

Applicability

Cited product scope

Trace impact →

9Underlying assertions

7Canonical products

9Target 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

Search scopeRoleOfficial link state

22 scope groups

microsoft · source assertedMicrosoftWindows Server 2008 R2 Service Pack 1Direct source scope

Affected: 6.1.7601.0 to before 6.1.7601.25769 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "6.1.7601.0", "lessThan": "6.1.7601.25769", "versionType": "custom"}]

microsoft · source assertedMicrosoftWindows Server 2008 R2 Service Pack 1 (Server Core installation)Direct source scope

Affected: 6.1.7601.0 to before 6.1.7601.25769 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "6.1.7601.0", "lessThan": "6.1.7601.25769", "versionType": "custom"}]

microsoft · source assertedMicrosoftWindows Server 2008 Service Pack 2Direct source scope

Affected: 6.0.6003.0 to before 6.0.6003.21282 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "6.0.6003.0", "lessThan": "6.0.6003.21282", "versionType": "custom"}]

microsoft · source assertedMicrosoftWindows Server 2008 Service Pack 2 (Server Core installation)Direct source scope

Affected: 6.0.6003.0 to before 6.0.6003.21282 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "6.0.6003.0", "lessThan": "6.0.6003.21282", "versionType": "custom"}]

microsoft · source assertedMicrosoftWindows Server 2012Direct source scope

Affected: 6.2.9200.0 to before 6.2.9200.23517 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "6.2.9200.0", "lessThan": "6.2.9200.23517", "versionType": "custom"}]

microsoft · source assertedMicrosoftWindows Server 2012 R2Direct source scope

Affected: 6.3.9600.0 to before 6.3.9600.20174 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "6.3.9600.0", "lessThan": "6.3.9600.20174", "versionType": "custom"}]

microsoft · source assertedMicrosoftWindows Server 2012 R2 (Server Core installation)Direct source scope

Affected: 6.3.9600.0 to before 6.3.9600.20174 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "6.3.9600.0", "lessThan": "6.3.9600.20174", "versionType": "custom"}]

microsoft · source assertedMicrosoftWindows Server 2012 (Server Core installation)Direct source scope

Affected: 6.2.9200.0 to before 6.2.9200.23517 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "6.2.9200.0", "lessThan": "6.2.9200.23517", "versionType": "custom"}]

microsoft · source assertedMicrosoftWindows Server 2016Direct source scope

Affected: 10.0.14393.0 to before 10.0.14393.4770 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "10.0.14393.0", "lessThan": "10.0.14393.4770", "versionType": "custom"}]

microsoft · source assertedMicrosoftWindows Server 2016 (Server Core installation)Direct source scope

Affected: 10.0.14393.0 to before 10.0.14393.4770 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "10.0.14393.0", "lessThan": "10.0.14393.4770", "versionType": "custom"}]

microsoft · source assertedMicrosoftWindows Server 2019Direct source scope

Affected: 10.0.17763.0 to before 10.0.17763.2300 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "10.0.17763.0", "lessThan": "10.0.17763.2300", "versionType": "custom"}]

microsoft · source assertedMicrosoftWindows Server 2019 (Server Core installation)Direct source scope

Affected: 10.0.17763.0 to before 10.0.17763.2300 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "10.0.17763.0", "lessThan": "10.0.17763.2300", "versionType": "custom"}]

microsoft · source assertedMicrosoftWindows Server 2022Direct source scope

Affected: 10.0.20348.0 to before 10.0.20348.350 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "10.0.20348.0", "lessThan": "10.0.20348.350", "versionType": "custom"}]

microsoft · source assertedMicrosoftWindows Server version 2004Direct source scope

Affected: 10.0.0 to before 10.0.19041.1348 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.19041.1348", "versionType": "custom"}]

microsoft · source assertedMicrosoftWindows Server version 20H2Direct source scope

Affected: 10.0.0 to before 10.0.19042.1348 (custom comparison)

Source-reported scope

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

Inspect raw assertion

[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.19042.1348", "versionType": "custom"}]

NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_2004Vulnerable target · 1 assertions

Any version (unconstrained) (< 10.0.19041.1348)Canonical identity product-571f6df0fa50d71be9551414060ed8bfcdb500437871cf9595b7fa6b034cecbdLinked exact

Scope supported

Inspect raw assertion

cpe:2.3:o:microsoft:windows_server_2004:*:*:*:*:*:*:*:*
Official link
Linked exact
Role
Vulnerable target
Configuration
0 · node/0 · match 0
Logic
OR
Version bounds
through excluding 10.0.19041.1348
Match ID
4cc5d95f-2823-475a-a466-1a4a5b328e88

NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_2008Vulnerable target · 2 assertions

Version not applicable; Version r2Canonical identity product-217b1ab3d25f361a639824f86753d418b35aa2a816ee370bb71b5d1dd883d87aLinked exact

Scope supported

Inspect raw assertions

cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*
Official link
Linked exact
Role
Vulnerable target
Configuration
0 · node/0 · match 2
Logic
OR
Version bounds
No explicit bounds
Match ID
af07a81d-12e5-4b1d-bff9-c8d08c32ff4f
cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:*
Official link
Linked exact
Role
Vulnerable target
Configuration
0 · node/0 · match 1
Logic
OR
Version bounds
No explicit bounds
Match ID
5f422a8c-2c4e-42c8-b420-e0728037e15c

NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_2012Vulnerable target · 2 assertions

Version not applicable; Version r2Canonical identity product-5a80416e92fed0cddbb3d4f3840218b448dee11159824ad25a0353da566963feLinked exact

Scope supported

Inspect raw assertions

cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
Official link
Linked exact
Role
Vulnerable target
Configuration
0 · node/0 · match 3
Logic
OR
Version bounds
No explicit bounds
Match ID
a7df96f8-ba6a-4780-9ca3-f719b3f81074
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
Official link
Linked exact
Role
Vulnerable target
Configuration
0 · node/0 · match 4
Logic
OR
Version bounds
No explicit bounds
Match ID
db18c4ce-5917-401e-acf7-2747084fd36e

NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_2016Vulnerable target · 1 assertions

Any version (unconstrained) (< 10.0.14393.4770)Canonical identity product-02e254d111ce604757a15650ef469f4f8365d6247da82ce3ac2695c3cfc7dc5fLinked exact

Scope supported

Inspect raw assertion

cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
Official link
Linked exact
Role
Vulnerable target
Configuration
0 · node/0 · match 5
Logic
OR
Version bounds
through excluding 10.0.14393.4770
Match ID
572bdefc-d3e8-4ff0-b91e-d21f42d2b82d

NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_2019Vulnerable target · 1 assertions

Any version (unconstrained) (< 10.0.17763.2300)Canonical identity product-25a2932c0bbcb648f7e391c8b9d34c734e5085444c03c1c206b9d4c4baa80b25Linked exact

Scope supported

Inspect raw assertion

cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
Official link
Linked exact
Role
Vulnerable target
Configuration
0 · node/0 · match 6
Logic
OR
Version bounds
through excluding 10.0.17763.2300
Match ID
74a5af5d-c59c-4093-a4c0-3be230e7637f

NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_2022Vulnerable target · 1 assertions

Any version (unconstrained) (< 10.0.20348.350)Canonical identity product-d196d31962e613955a91e33e795c22dcfa7bf25173abebaca616a6350cce9ce1Linked exact

Scope supported

Inspect raw assertion

cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
Official link
Linked exact
Role
Vulnerable target
Configuration
0 · node/0 · match 7
Logic
OR
Version bounds
through excluding 10.0.20348.350
Match ID
b662e504-15e6-4d85-8463-bbe9435790cc

NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_20h2Vulnerable target · 1 assertions

Any version (unconstrained) (< 10.0.19042.1348)Canonical identity product-457c0c3b89fb1cf896e8491223eac8b0cb1ea61ce3174f915e4fe1032759d5a2Linked exact

Scope supported

Inspect raw assertion

cpe:2.3:o:microsoft:windows_server_20h2:*:*:*:*:*:*:*:*
Official link
Linked exact
Role
Vulnerable target
Configuration
0 · node/0 · match 8
Logic
OR
Version bounds
through excluding 10.0.19042.1348
Match ID
81674128-32b2-4825-8e69-6047db81134c

Affected-product evidence

Accepted scope and product mapping

0 canonical links · 2 source-reported links

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: 15
Mapping revision: cpe23-exact-mapping-v1
Observed cutoff: Oct 22, 2026

Retained assertion IDs

376aed4c-4fb3-49f3-a6d0-15035c307c58557abebd-6ca9-49b6-8c51-b12016c7ac81658f2463-3dfa-4b96-a9d3-d9b087ceb41a69354d54-85aa-4b77-96b2-3e8d4b8b832075f12d96-58ce-4c22-9258-e8a3c80cf3c1801047fc-42e8-4e85-a9d6-ade8a8ddb122a571d030-4fc6-4d61-958d-d935e41375d9b9713c8a-c489-41f2-a327-580fba3e6c21bc1447c6-4ee6-4c6c-b9d6-144b5aa68b22bed8037d-b4b1-4d3e-81b9-5d6a3fb8bbd7cdbd968e-72e6-4235-8972-f92fe3a92acaebe540c8-88d0-441f-8b25-ddebc6c144dcf21c7a9f-2aee-470c-b9b4-33de61f73a89f3926cd7-db80-4584-9638-b921df776141f7ebb15f-cff1-4cf9-a4f0-113cddb1d5c3

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: Nvd cpe vulnerable target
Assertions: 9
Mapping revision: cpe23-exact-mapping-v1
Observed cutoff: Oct 22, 2026

Retained assertion IDs

0828026e-3627-4219-8f9a-3475b52706263a226b6b-c2f5-4b72-9481-59e659b556584575a3f0-c35a-4b67-819c-85c4dbbe19555f08c607-6234-4786-9a35-047bacfc29fcabed0595-f108-445d-bbb4-2f1af80befeeae1b46fe-db08-4d2c-a4e3-b18a13a8bf5bc28e86b3-9a1f-4909-993c-8508037fe6f3e79c3a7c-fb9f-40c8-b27e-a943287e18c2f46c466f-0812-4763-bd82-50b6dc9f95a3

Assessments

CVSS by origin

6.5

NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:N/AC:L/Au:S/C:P/I:P/A:P

7.5

NVDCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

7.5

secure@microsoft.comCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

7.5

microsoftCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Direct CVE/CNA normalized decisions

7.5Priority eligible

microsoft

CVSS 3.1 · Primary · Original assertion · rank 1

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Validation: Valid match
Recomputed: 7.5
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.