Evidence dossier
CVE-2021-34448
Scripting Engine Memory Corruption Vulnerability
Exploited in the wild (CISA KEV since Nov 3, 2021). microsoft reports CVSS 3.1 6.8. Severity assessments differ within at least one CVSS version. EPSS estimates 40.1% exploit likelihood as of Aug 27, 2026.
As of Aug 27, 2026
Normalized restatement
Scripting Engine Memory Corruption Vulnerability
- State
- PUBLISHED
- Published
- Jul 16, 2021
- Updated
- Oct 21, 2025
- Evidence coverage
- 80%
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: Scripting Engine Memory Corruption Vulnerability
Inspect raw assertion
- Field
container- Value
- Scripting Engine Memory Corruption Vulnerability
- Source dateFirst observed by CASCACISA KEVOriginal evidence ↗
Exploitation cataloged: Microsoft Windows Scripting Engine Memory Corruption Vulnerability
Inspect raw assertion
- Field
observed_exploitation- Value
- Microsoft Windows Scripting Engine Memory Corruption Vulnerability
- Source dateFirst observed by CASCAFIRST EPSSOriginal evidence ↗
EPSS score: 40.06% probability · 98.52th percentile
Inspect raw assertion
- Field
model_probability- Value
- Probability 0.400620000000; percentile 0.985250000000
Assessments differ
Values are shown separately by source and CVSS version.
CISA KEV · catalog date Nov 3, 2021 · first observed Jul 19, 2026
FIRST EPSS · score date Aug 27, 2026 · 98.5th percentile · first observed Aug 27, 2026
microsoft · CVSS 3.1 · first observed Jul 19, 2026 · values shown separately below
Evidence detail
Source limits and decisions
Why each evidence state has this value
casca-unknown-reasons-v1Eligible evidence is present for this bounded claim.
- Revision
- evidence-policy-v1.1.0
- Cutoff
- Aug 27, 2026
- Resolution
- None
Eligible evidence is present for this bounded claim.
- Revision
- evidence-policy-v1.1.0
- Cutoff
- Aug 27, 2026
- Resolution
- None
Eligible assertions materially conflict and remain visible side by side.
- Revision
- casca-direct-cvss-eligibility-v1
- Cutoff
- Aug 27, 2026
- Resolution
- Resolve conflict
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 ADP Vulnrichment
Inspect raw assertion
- Field
container- Value
- CISA ADP Vulnrichment
CVE Program Container
Inspect raw assertion
- Field
container- Value
- CVE Program Container
Scripting Engine Memory Corruption Vulnerability
Inspect raw assertion
- Field
container- Value
- Scripting Engine Memory Corruption Vulnerability
Microsoft Windows Scripting Engine Memory Corruption Vulnerability
Inspect raw assertion
- Field
observed_exploitation- Value
- Microsoft Windows Scripting Engine Memory Corruption Vulnerability
40.06% probability · 98.52th percentile
Inspect raw assertion
- Field
model_probability- Value
- Probability 0.400620000000; percentile 0.985250000000
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
29 scope groups
Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.10240.19003", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.14393.4530", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.17763.2061", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.18363.1679", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.19041.1110", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.19042.1110", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.19043.1110", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "6.1.0", "lessThan": "6.1.7601.25661", "versionType": "custom"}, {"status": "affected", "version": "6.1.0", "lessThan": "1.001", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "6.1.0", "lessThan": "6.1.7601.25661", "versionType": "custom"}, {"status": "affected", "version": "6.1.0", "lessThan": "1.001", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "6.3.0", "lessThan": "6.3.9600.20069", "versionType": "custom"}, {"status": "affected", "version": "6.3.0", "lessThan": "1.001", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "6.1.0", "lessThan": "6.1.7601.25661", "versionType": "custom"}, {"status": "affected", "version": "6.1.0", "lessThan": "1.001", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "6.2.0", "lessThan": "6.2.9200.23409", "versionType": "custom"}, {"status": "affected", "version": "6.2.0", "lessThan": "1.001", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "6.3.0", "lessThan": "6.3.9600.20069", "versionType": "custom"}, {"status": "affected", "version": "6.3.0", "lessThan": "1.001", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.14393.4530", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.0", "lessThan": "10.0.17763.2061", "versionType": "custom"}]product-9851bd571b8ab08bca589cd73710badfef557d036f0fb7707f694f1c9f597cb4Linked exactInspect raw assertion
cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 0 · node/0 · match 0
- Logic
- OR
- Version bounds
- through excluding 10.0.10240.19003
- Match ID
0c51cd3a-e78b-4a0d-8716-4f2c0a79ed68
product-740fec3e9838b5eabe76ebe27e4d0d7a4cb2e0ef7e13923300d3d0b51e3fce1cLinked exactInspect raw assertion
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 0 · node/0 · match 1
- Logic
- OR
- Version bounds
- through excluding 10.0.14393.4530
- Match ID
9eebf8ac-ab6e-4f62-811a-0e53721c78f5
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 2
- Logic
- OR
- Version bounds
- through excluding 10.0.17763.2061
- Match ID
5baabe12-c0e8-4e34-9efe-18dd50c54b1d
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 3
- Logic
- OR
- Version bounds
- through excluding 10.0.18363.1679
- Match ID
1c9e359b-5719-48b1-babb-618744c73388
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 4
- Logic
- OR
- Version bounds
- through excluding 10.0.19041.1110
- Match ID
307c13cf-563b-46d1-9f2e-227ab9c40720
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 5
- Logic
- OR
- Version bounds
- through excluding 10.0.19042.1110
- Match ID
9aec53c7-c1cb-4ffb-8069-27604fb50f0b
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 6
- Logic
- OR
- Version bounds
- through excluding 10.0.19043.1110
- Match ID
765ba052-1b41-4cd3-98e6-f3750e0466e5
product-f20a05098a41a238f96b56b817d0482887bb39ad40620198bbe05da10ee02ffcLinked exactInspect raw assertion
cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 0 · node/0 · match 7
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
c2b1c231-de19-4b8f-a4aa-5b3a65276e46
product-7e46de82012029583622f69d79b86bc210b5bd25b8cb3bb4468936702b23c4b0Linked exactInspect raw assertion
cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 0 · node/0 · match 8
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
e93068db-549b-45ab-8e5c-00eb5d8b5cf8
product-076c7e47c78d9425d54dea0b063ed7cd79e5f9f0bfdb3c9153b8aec4e71a7ad9Linked exactInspect raw assertion
cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*- Official link
- Linked exact
- Role
- Vulnerable target
- Configuration
- 0 · node/0 · match 9
- Logic
- OR
- Version bounds
- No explicit bounds
- Match ID
c6ce5198-c498-4672-af4c-77ab4be06c5c
Affected-product evidence
Accepted scope and product mapping
14 canonical links · 1 source-reported links
vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-02e254d111ce604757a15650ef469f4f8365d6247da82ce3ac2695c3cfc7dc5f
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
1161137d-bb69-4156-bd1b-c30bbf25ca1cvendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-076c7e47c78d9425d54dea0b063ed7cd79e5f9f0bfdb3c9153b8aec4e71a7ad9
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
c0bd1db4-ebcf-4521-8e3b-19aca6e8e041vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-217b1ab3d25f361a639824f86753d418b35aa2a816ee370bb71b5d1dd883d87a
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
9032273f-2264-4da5-8f41-0bd14b763bc7vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-25a2932c0bbcb648f7e391c8b9d34c734e5085444c03c1c206b9d4c4baa80b25
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
6a26f414-fb74-456c-949f-ca62eb596322vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-55e90faed8848f3d316cf702d119e83086b6dc5a963d9947a7df1c589f50346d
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
d6f8df5d-6a10-42e2-9f92-6b46067787dbvendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-5a80416e92fed0cddbb3d4f3840218b448dee11159824ad25a0353da566963fe
- Source class
- Nvd cpe vulnerable target
- Assertions
- 2
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
bfccfbb3-f9e7-485c-92d1-9da7582dc186f87de683-81f8-4749-b681-62fcebe344c8vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-740fec3e9838b5eabe76ebe27e4d0d7a4cb2e0ef7e13923300d3d0b51e3fce1c
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
c2564693-2c4c-41d5-ba1d-7e31c2d7a818vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-7e46de82012029583622f69d79b86bc210b5bd25b8cb3bb4468936702b23c4b0
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
890eda29-2191-4c55-8369-065d4eeee55bvendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-9851bd571b8ab08bca589cd73710badfef557d036f0fb7707f694f1c9f597cb4
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
a72bd1ef-c5ce-40aa-9322-d6ee71e20187vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-9b245936275be71b526838fc72ea633d195b35bdd9dfc31bb6df51e7700edecc
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
a68f0630-0541-4dfd-8215-2429c3cee7d6vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-a3084138383423221f61594e86f5b295e5e254acd7ae5284f45e0877a084db43
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
39630963-7c72-40bc-832e-717f1cd4fa1fvendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-e0c6c3f5c5e95b5b83fbbf719a7de2471749e1ca250bebf19bc7898a937a00ed
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
987dea32-98aa-45c4-b181-cdf9f35d4a48vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-ef5324dcc791e4e872d6c2be0aefa1d7687ca82c3b4ac5d1f72c76cce8395218
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
c79be339-afd8-4fa4-be20-05497d3c7e2bvendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-f20a05098a41a238f96b56b817d0482887bb39ad40620198bbe05da10ee02ffc
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
1356d739-c850-4868-9713-2e8918017d51Canonical 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
- Aug 27, 2026
Retained assertion IDs
2ff1b4c0-86d3-4269-acee-1e8f1e2fb14b36305f8e-d342-417c-a758-4c691ad8295c3c4dde36-24bc-4c8e-9f59-e9b954fc576a511f15d1-34d5-4698-b2f8-a47451db819d6a959b04-caef-484f-bf45-bcf3c27bf53f71660477-536f-4048-b154-15ee99673c3597eeaab3-3966-451a-98db-688d460568c29b36f7f1-c8fc-4388-afdc-1ab960e4d01c9b629d05-a3f9-4ff4-ac03-e3fec392edf89e67f2c0-f469-4af3-bddd-4b577fb394d2a6db597e-d463-4a47-b541-fa1c3cec0b4ebff41864-b004-409e-952e-306827538291c443478e-ad8d-4940-936a-a60bf67aaf16da7f24af-9add-46ee-bca3-d1230281a2b7e3b8af85-567b-4261-b363-8fbb49ef1e05Assessments
CVSS by origin
AV:N/AC:M/Au:N/C:C/I:C/A:CCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:NCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N/E:F/RL:O/RC:CDirect CVE/CNA normalized decisions
microsoft
CVSS 3.1 · Primary · Original assertion · rank 1
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N/E:F/RL:O/RC:C- Validation
- Valid match
- Recomputed
- 6.8
- 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.