CASCACascade Atlas

Evidence dossier

CVE-2020-0796

A remote code execution vulnerability exists in the way that the Microsoft Server Message Block 3.1.1 (SMBv3) protocol handles certain requests, aka 'Windows SMBv3…

Exploited in the wild (CISA KEV since Feb 10, 2022). NVD reports CVSS 3.1 10.0. EPSS estimates 99.8% exploit likelihood as of Aug 6, 2026.

89.6–94.3Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

A remote code execution vulnerability exists in the way that the Microsoft Server Message Block 3.1.1 (SMBv3) protocol handles certain requests, aka 'Windows SMBv3 Client/Server Remote Code Execution Vulnerability'.

State
PUBLISHED
Published
Mar 12, 2020
Updated
Oct 21, 2025
Evidence coverage
92%

Evidence chronology

What was known when

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  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: A remote code execution vulnerability exists in the way that the Microsoft Server Message Block 3.1.1 (SMBv3) protocol handles certain requests, aka 'Windows SMBv3 Client/Server Remote Code Execution Vulnerability'.

    Inspect raw assertion
    Field
    container
    Value
    A remote code execution vulnerability exists in the way that the Microsoft Server Message Block 3.1.1 (SMBv3) protocol handles certain requests, aka 'Windows SMBv3 Client/Server Remote Code Execution Vulnerability'.
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Microsoft SMBv3 Remote Code Execution Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Microsoft SMBv3 Remote Code Execution Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 99.81% probability · 99.96th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.998100000000; percentile 0.999580000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Feb 10, 2022 · first observed Jul 19, 2026

Exploit likelihood99.81%

FIRST EPSS · score date Aug 6, 2026 · 100th percentile · first observed Aug 6, 2026

SeverityCVSS 10.0

NVD · 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

A remote code execution vulnerability exists in the way that the Microsoft Server Message Block 3.1.1 (SMBv3) protocol handles certain requests, aka 'Windows SMBv3 Client/Server Remote Code Execution Vulnerability'.

Inspect raw assertion
Field
container
Value
A remote code execution vulnerability exists in the way that the Microsoft Server Message Block 3.1.1 (SMBv3) protocol handles certain requests, aka 'Windows SMBv3 Client/Server Remote Code Execution Vulnerability'.
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

Microsoft SMBv3 Remote Code Execution Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Microsoft SMBv3 Remote Code Execution Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

99.81% probability · 99.96th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.998100000000; percentile 0.999580000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
8Underlying assertions
4Canonical products
8Target 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

12 scope groups

microsoft · source assertedMicrosoftWindows 10 Version 1903 for 32-bit SystemsDirect source scope
Affected: unspecified
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "unspecified"}]
microsoft · source assertedMicrosoftWindows 10 Version 1903 for ARM64-based SystemsDirect source scope
Affected: unspecified
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "unspecified"}]
microsoft · source assertedMicrosoftWindows 10 Version 1903 for x64-based SystemsDirect source scope
Affected: unspecified
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "unspecified"}]
microsoft · source assertedMicrosoftWindows 10 Version 1909 for 32-bit SystemsDirect source scope
Affected: unspecified
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "unspecified"}]
microsoft · source assertedMicrosoftWindows 10 Version 1909 for ARM64-based SystemsDirect source scope
Affected: unspecified
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "unspecified"}]
microsoft · source assertedMicrosoftWindows 10 Version 1909 for x64-based SystemsDirect source scope
Affected: unspecified
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "unspecified"}]
microsoft · source assertedMicrosoftWindows Server, version 1903 (Server Core installation)Direct source scope
Affected: unspecified
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "unspecified"}]
microsoft · source assertedMicrosoftWindows Server, version 1909 (Server Core installation)Direct source scope
Affected: unspecified
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "unspecified"}]
NVD CPE · OPERATING SYSTEMmicrosoftwindows_10_1903Vulnerable target · 3 assertions
Version not applicableCanonical identity product-9868fa1c12254f9aff51c0302ecb2ea1ab1d9ca0547bde09677154b24f8c7c61Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:microsoft:windows_10_1903:-:*:*:*:*:*:arm64:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    9e1ed169-6f03-4bd5-b227-5fa54db40ad7
  2. cpe:2.3:o:microsoft:windows_10_1903:-:*:*:*:*:*:x86:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 2
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    b6a0db01-49cb-4445-afe8-57c2186857ba
  3. cpe:2.3:o:microsoft:windows_10_1903:-:*:*:*:*:*:x64:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    5c5b5180-1e12-45c2-8275-b9e528955307
NVD CPE · OPERATING SYSTEMmicrosoftwindows_10_1909Vulnerable target · 3 assertions
Version not applicableCanonical identity product-ef5324dcc791e4e872d6c2be0aefa1d7687ca82c3b4ac5d1f72c76cce8395218Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:microsoft:windows_10_1909:-:*:*:*:*:*:arm64:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 3
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    9285a9b5-4759-43e7-9589-cdbca7100605
  2. cpe:2.3:o:microsoft:windows_10_1909:-:*:*:*:*:*:x64:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 4
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    0d77ea14-f61d-4b9e-a385-70b88c482116
  3. cpe:2.3:o:microsoft:windows_10_1909:-:*:*:*:*:*:x86:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 5
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    1a6fc9ee-d486-4afe-a20e-4278468a1779
NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_1903Vulnerable target · 1 assertions
Version not applicableCanonical identity product-14b069f5c38c7de633daa144529d27da601f26ac1be85dea8792e6a0093a122bLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_server_1903:-:*:*:*:*:*:x64:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 6
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    ffe3495d-291c-46b6-b758-23e16a53a7c3
NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_1909Vulnerable target · 1 assertions
Version not applicableCanonical identity product-11ee14cb5467893e953fd2afd492aa2a80b330b2831c4c10e31a6d9476b8f7abLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_server_1909:-:*:*:*:*:*:x64:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 7
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    11e7f8f0-4fa8-4aa6-92a5-860e77ac933d

Affected-product evidence

Accepted scope and product mapping

4 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-11ee14cb5467893e953fd2afd492aa2a80b330b2831c4c10e31a6d9476b8f7ab

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
2f116494-8eb5-4ebc-8b49-c9927fb74df2
Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-14b069f5c38c7de633daa144529d27da601f26ac1be85dea8792e6a0093a122b

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
37e2e398-13b5-4aad-b205-c1d7bfe1eeb4
Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-9868fa1c12254f9aff51c0302ecb2ea1ab1d9ca0547bde09677154b24f8c7c61

Source class
Nvd cpe vulnerable target
Assertions
3
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
5a8eb731-2b61-47c5-8467-9a573046135499752775-7c80-482f-8b0e-5f46845e4461ce1ce101-89c5-4fe9-8fe4-60a6454aa9cc
Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-ef5324dcc791e4e872d6c2be0aefa1d7687ca82c3b4ac5d1f72c76cce8395218

Source class
Nvd cpe vulnerable target
Assertions
3
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
31f6aea4-4c17-494e-93f7-f572b82af67fbe1847d7-6152-412e-b6a1-46cdc6f08725be7ad487-12c5-4c37-937c-eebe134f05eb
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
8
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
0fa2aa94-83f9-48df-81a3-fbbd64755998145e4f39-27df-4161-a657-342731b20dfc2821d300-644a-4ed4-b7eb-518891b8bcd26ac49aea-35ad-41bb-a70d-f6e1ea32fb74757e6d01-e2f2-46dd-a0df-9d570fccdcb3e17fa410-6de5-44ba-a2c5-6e26b54d9d82ef442031-3bf0-4e78-a641-49ac16e01ed2fdb28061-16f7-4e6e-80da-b64f47dd323f

Assessments

CVSS by origin

10.0
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
7.5
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:N/AC:L/Au:N/C:P/I:P/A:P
10.0
CVE Program sourceCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
10.0
CISA-ADPCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Direct CVE/CNA normalized decisions

10.0Priority eligible

CISA-ADP

CVSS 3.1 · Secondary · Independent enrichment · rank 2

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Validation
Valid match
Recomputed
10.0
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.