CISA KEV · catalog date Feb 11, 2025 · first observed Jul 19, 2026
Evidence dossier
CVE-2025-21418
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
Exploited in the wild (CISA KEV since Feb 11, 2025). microsoft reports CVSS 3.1 7.8. EPSS estimates 1.5% exploit likelihood as of Aug 27, 2026.
As of Aug 27, 2026
Normalized restatement
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
- State
- PUBLISHED
- Published
- Feb 11, 2025
- Updated
- Feb 26, 2026
- Evidence coverage
- 91%
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 CASCAmicrosoftOriginal evidence ↗
Record text: Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
Inspect raw assertion
- Field
container- Value
- Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
- Source dateFirst observed by CASCACISA KEVOriginal evidence ↗
Exploitation cataloged: Microsoft Windows Ancillary Function Driver for WinSock Heap-Based Buffer Overflow Vulnerability
Inspect raw assertion
- Field
observed_exploitation- Value
- Microsoft Windows Ancillary Function Driver for WinSock Heap-Based Buffer Overflow Vulnerability
- Source dateFirst observed by CASCAFIRST EPSSOriginal evidence ↗
EPSS score: 1.54% probability · 73.02th percentile
Inspect raw assertion
- Field
model_probability- Value
- Probability 0.015370000000; percentile 0.730220000000
FIRST EPSS · score date Aug 27, 2026 · 73th percentile · first observed Aug 27, 2026
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-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 evidence is present for this bounded claim.
- Revision
- casca-direct-cvss-eligibility-v1
- Cutoff
- Aug 27, 2026
- Resolution
- None
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
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
Inspect raw assertion
- Field
container- Value
- Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
Microsoft Windows Ancillary Function Driver for WinSock Heap-Based Buffer Overflow Vulnerability
Inspect raw assertion
- Field
observed_exploitation- Value
- Microsoft Windows Ancillary Function Driver for WinSock Heap-Based Buffer Overflow Vulnerability
1.54% probability · 73.02th percentile
Inspect raw assertion
- Field
model_probability- Value
- Probability 0.015370000000; percentile 0.730220000000
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
39 scope groups
Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.10240.0", "lessThan": "10.0.10240.20915", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.14393.0", "lessThan": "10.0.14393.7785", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.17763.0", "lessThan": "10.0.17763.6893", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.19044.0", "lessThan": "10.0.19044.5487", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.19045.0", "lessThan": "10.0.19045.5487", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.22621.0", "lessThan": "10.0.22621.4890", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.22631.0", "lessThan": "10.0.22631.4890", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.22631.0", "lessThan": "10.0.22631.4890", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.3194", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "6.1.7601.0", "lessThan": "6.1.7601.27566", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "6.1.7601.0", "lessThan": "6.1.7601.27566", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "6.0.6003.0", "lessThan": "6.0.6003.23117", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "6.0.6003.0", "lessThan": "6.0.6003.23117", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "6.2.9200.0", "lessThan": "6.2.9200.25317", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "6.3.9600.0", "lessThan": "6.3.9600.22417", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "6.3.9600.0", "lessThan": "6.3.9600.22417", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "6.2.9200.0", "lessThan": "6.2.9200.25317", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.14393.0", "lessThan": "10.0.14393.7785", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.14393.0", "lessThan": "10.0.14393.7785", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.17763.0", "lessThan": "10.0.17763.6893", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.17763.0", "lessThan": "10.0.17763.6893", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.20348.0", "lessThan": "10.0.20348.3207", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.25398.0", "lessThan": "10.0.25398.1425", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.3194", "versionType": "custom"}]Canonical linkage remains open; the cited source assertion is retained below.
Inspect raw assertion
[{"status": "affected", "version": "10.0.26100.0", "lessThan": "10.0.26100.3194", "versionType": "custom"}]Affected-product evidence
Accepted scope and product mapping
14 canonical links · 1 source-reported links
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
2dcf6080-9d10-4b7a-bd65-708586028a08vendor-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
972dce49-8244-41ec-863a-bb3f7dcf8a61vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-217b1ab3d25f361a639824f86753d418b35aa2a816ee370bb71b5d1dd883d87a
- Source class
- Nvd cpe vulnerable target
- Assertions
- 2
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
8fbc5d52-2b3a-4661-9612-1bbf15ee51b7a8e0fd52-0a33-4a4f-9928-dbd24631e0e3vendor-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
bd554dfa-88fd-46bb-9a74-c7493791b19dvendor-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
0568e199-9e4d-411d-8a97-2c5eccd982eevendor-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
9f273b73-fdb8-4a4c-a31a-9a94748a39e5ff4d65cb-c055-4634-8267-02f916dd607dvendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-740fec3e9838b5eabe76ebe27e4d0d7a4cb2e0ef7e13923300d3d0b51e3fce1c
- Source class
- Nvd cpe vulnerable target
- Assertions
- 2
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
0a672f3f-cc78-47ea-8480-2fecbc68be92496e0bb1-df2b-4c1d-b6d7-307867952608vendor-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
8ecf452b-f96d-4c4f-a40e-2356a0541273vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-a3084138383423221f61594e86f5b295e5e254acd7ae5284f45e0877a084db43
- Source class
- Nvd cpe vulnerable target
- Assertions
- 2
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
3f82a694-01c2-415c-9cec-37bca127d75b5e86782e-eada-4564-9127-878e107d32cbvendor-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
f30add87-d57b-4f89-9ec9-79d2b8b8b99dvendor-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
54f7d9c0-1f8a-4f28-a798-bdcbb759c8cdvendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-d196d31962e613955a91e33e795c22dcfa7bf25173abebaca616a6350cce9ce1
- Source class
- Nvd cpe vulnerable target
- Assertions
- 1
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
29fcb2bc-616e-4281-8dd4-dc054e87e03bvendor-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
f69586f0-3a14-447d-8e15-a8bdaf6d7018vendor-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
3640d301-dd4d-41c5-9ec2-5f86eaf67e88Canonical 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
- 25
- Mapping revision
- cpe23-exact-mapping-v1
- Observed cutoff
- Aug 27, 2026
Retained assertion IDs
1c233d00-9a0e-4e5c-9889-cdddc133239821ffa469-0e0e-487f-8550-9856a59ad4cc3d185938-d851-4a5a-916f-7e93a4931bbf530f52c7-ff55-4aea-b819-9589ff918c9f58480950-a324-410f-b597-783394d0682b6127d1f7-3e5e-4db8-a6d2-884eb64598356ce4b00f-0c9d-48e5-a6c8-d8a805ed08736df41703-58e7-4682-a76a-18b4f36e97c77b931cae-ff6e-4375-8cea-a6e1206e70a87e835c37-48bc-4e1c-911d-1c732a6c701a81a76965-9d74-43a7-938f-ade2c64baf12895964ae-0ea3-4ac1-896c-9d46b7b21a8090a87bab-a378-44bb-8265-935bb5253cb39934df8b-c180-48c4-a3f3-4246c20364bba0deddac-d116-458d-a64c-6eacaa1cf1e9a7c2de59-bd24-453e-9754-6dd569dbabf0acc5395d-0015-4312-a2a4-ed50023902ecc1cccebd-0d7c-44eb-a4b2-3e8b9e4b3458c89b82b2-760c-4c16-9f2f-e36f728909ebdadde8b0-5bb6-47c0-a03d-cf471ff3f8dcdf6ab950-c451-46b8-8ebb-f73a0001a872e8625fcb-3bc7-488c-8230-f8437eb7831de8b464a0-e09e-4a25-abc3-09ff5293b6aaef66e4c9-3e23-42e4-bf48-42e40426a8dafc158349-c079-4bfa-bda3-eaa4b2ad437fAssessments
CVSS by origin
CVSS: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:O/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: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.