CISA KEV · catalog date Feb 10, 2022 · first observed Sep 1, 2026
Evidence dossier
CVE-2021-36934
Windows Elevation of Privilege Vulnerability
Exploited in the wild (CISA KEV since Feb 10, 2022). microsoft reports CVSS 3.1 7.8. EPSS estimates 67.3% exploit likelihood as of Oct 21, 2026.
As of Oct 22, 2026
Normalized restatement
An elevation of privilege vulnerability exists because of overly permissive Access Control Lists (ACLs) on multiple system files, including the Security Accounts Manager (SAM) database. An attacker who successfully exploited this vulnerability could run arbitrary code with SYSTEM privileges. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. An attacker must have the ability to execute code on a victim system to exploit this vulnerability. After installing this security update, you must manually delete all shadow copies of system files, including the SAM database, to fully mitigate this vulnerabilty. Simply installing this security update will not fully mitigate this vulnerability. See KB5005357- Delete Volume Shadow Copies.
- State
- PUBLISHED
- Published
- Jul 22, 2021
- Updated
- Aug 10, 2026
- Evidence coverage
- 85%
Evidence chronology
What was known when
- Source dateSource date omittedFirst observed by CASCACISA-ADPOriginal evidence ↗
Record text: CISA ADP Vulnrichment
Inspect raw assertion
- Field
container- Value
- CISA ADP Vulnrichment
- Source dateSource date omittedFirst observed by CASCACVE ProgramOriginal evidence ↗
Record text: CVE Program Container
Inspect raw assertion
- Field
container- Value
- CVE Program Container
- Source dateSource date omittedFirst observed by CASCAmicrosoftOriginal evidence ↗
Record text: Windows Elevation of Privilege Vulnerability
Inspect raw assertion
- Field
container- Value
- Windows Elevation of Privilege Vulnerability
- Source dateFirst observed by CASCACISA KEVOriginal evidence ↗
Exploitation cataloged: Microsoft Windows SAM Local Privilege Escalation Vulnerability
Inspect raw assertion
- Field
observed_exploitation- Value
- Microsoft Windows SAM Local Privilege Escalation Vulnerability
- Source dateFirst observed by CASCAFIRST EPSSOriginal evidence ↗
EPSS score: 67.25% probability · 99.3th percentile
Inspect raw assertion
- Field
model_probability- Value
- Probability 0.672520000000; percentile 0.993040000000
FIRST EPSS · score date Oct 21, 2026 · 99.3th percentile · first observed Oct 21, 2026
microsoft · CVSS 3.1 · first observed Aug 10, 2026 · same-version scores align in this snapshot
Evidence detail
Source limits and decisions
Why each evidence state has this value
casca-unknown-reasons-v1The last verified source boundary remains in force for this claim.
- Revision
- evidence-policy-v1.1.0
- Cutoff
- Oct 22, 2026
- Resolution
- Review source contract
Eligible evidence is present for this bounded claim.
- Revision
- evidence-policy-v1.1.0
- Cutoff
- Oct 22, 2026
- Resolution
- None
Eligible evidence is present for this bounded claim.
- Revision
- casca-direct-cvss-eligibility-v1
- Cutoff
- Oct 22, 2026
- Resolution
- None
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 ADP Vulnrichment
Inspect raw assertion
- Field
container- Value
- CISA ADP Vulnrichment
CVE Program Container
Inspect raw assertion
- Field
container- Value
- CVE Program Container
Windows Elevation of Privilege Vulnerability
Inspect raw assertion
- Field
container- Value
- Windows Elevation of Privilege Vulnerability
Microsoft Windows SAM Local Privilege Escalation Vulnerability
Inspect raw assertion
- Field
observed_exploitation- Value
- Microsoft Windows SAM Local Privilege Escalation Vulnerability
67.25% probability · 99.3th percentile
Inspect raw assertion
- Field
model_probability- Value
- Probability 0.672520000000; percentile 0.993040000000
Applicability
Cited product scope
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 2026-07-21T06:45:29.809Z
27d65b0f-b718-4b4f-bb79-c47c68d09dfa - Cpe match643,502 records · observed through 2026-07-21T08:13:17.697Z
955dae73-7302-438b-aee1-058d7cc5d48e
11 scope groups
Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.17763.0", "lessThan": "10.0.17763.2114", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.17763.2114", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.18363.1734", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.19041.1165", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.19042.1165", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.19043.1165", "versionType": "custom"}]product-a3084138383423221f61594e86f5b295e5e254acd7ae5284f45e0877a084db43Linked exactInspect raw assertion
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 0 · node/0 · match 0
- Logic
- OR
- Version bounds
- through excluding 10.0.17763.2114
- Match ID
f8d40d82-1d88-4cf1-b961-f9f28426c56b
product-ef5324dcc791e4e872d6c2be0aefa1d7687ca82c3b4ac5d1f72c76cce8395218Linked exactInspect raw assertion
cpe:2.3:o:microsoft:windows_10_1909:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 0 · node/0 · match 1
- Logic
- OR
- Version bounds
- through excluding 10.0.18363.1734
- Match ID
3dd2bde6-67c6-48e2-bed0-12e4cc7ee6bc
product-9b245936275be71b526838fc72ea633d195b35bdd9dfc31bb6df51e7700edeccLinked exactInspect raw assertion
cpe:2.3:o:microsoft:windows_10_2004:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 0 · node/0 · match 2
- Logic
- OR
- Version bounds
- through excluding 10.0.19041.1165
- Match ID
70336a6a-de45-4604-be81-10da4df12d3f
product-55e90faed8848f3d316cf702d119e83086b6dc5a963d9947a7df1c589f50346dLinked exactInspect raw assertion
cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 0 · node/0 · match 3
- Logic
- OR
- Version bounds
- through excluding 10.0.19042.1165
- Match ID
7ab7321a-1f89-48b3-8e5a-94791ab2bc86
product-e0c6c3f5c5e95b5b83fbbf719a7de2471749e1ca250bebf19bc7898a937a00edLinked exactInspect raw assertion
cpe:2.3:o:microsoft:windows_10_21h1:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 0 · node/0 · match 4
- Logic
- OR
- Version bounds
- through excluding 10.0.19043.1165
- Match ID
2a860f2b-0533-46f7-879e-b932e4e44f0d
Affected-product evidence
Accepted scope and product mapping
0 canonical links · 2 source-reported links
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
- 6
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Oct 22, 2026
Retained assertion IDs
03b6183a-f587-4324-9397-e5c17c4018e6537742ee-771d-4bb2-9ce0-bcc5b12be730792566ed-a4eb-4686-8ac0-88080de2c471853bb1ea-beb9-4e58-9784-352907afefd3f3862a28-5b21-4824-bdb7-184a36fe524cf560496d-9dba-458c-a39b-3d0c518bd6c3Canonical 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
- 5
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Oct 22, 2026
Retained assertion IDs
0e85b1ac-1232-4901-b661-14af837ab09c451365bd-8bf4-48c5-beda-7317468917fd4c276262-4ce9-48e6-9200-7f209cf0dcfce7bc9890-cdc0-430c-904b-3cd85d5d9347f5981ef8-0756-49dc-8b33-129442cf50e3Assessments
CVSS by origin
AV:L/AC:L/Au:N/C:P/I:P/A:PCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:F/RL:T/RC:CDirect CVE/CNA normalized decisions
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:F/RL:T/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.