Evidence dossier

CVE-2020-1350

A remote code execution vulnerability exists in Windows Domain Name System servers when they fail to properly handle requests, aka 'Windows DNS Server Remote Code Execution…

Exploited in the wild (CISA KEV since Nov 3, 2021). NVD reports CVSS 3.1 10.0. EPSS estimates 91.4% exploit likelihood as of Aug 18, 2026.

88.791.8Priority 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 Windows Domain Name System servers when they fail to properly handle requests, aka 'Windows DNS Server Remote Code Execution Vulnerability'.

State
PUBLISHED
Published
Jul 14, 2020
Updated
Oct 21, 2025
Evidence coverage
94%

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 Windows Domain Name System servers when they fail to properly handle requests, aka 'Windows DNS Server Remote Code Execution Vulnerability'.

    Inspect raw assertion
    Field
    container
    Value
    A remote code execution vulnerability exists in Windows Domain Name System servers when they fail to properly handle requests, aka 'Windows DNS Server Remote Code Execution Vulnerability'.
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Microsoft Windows DNS Server Remote Code Execution Vulnerability

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

    EPSS score: 91.35% probability · 99.8th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.913530000000; percentile 0.998030000000
    Original evidence ↗
ExploitationCatalog member

CISA KEV · catalog date Nov 3, 2021 · first observed Jul 19, 2026

Exploit likelihood91.35%

FIRST EPSS · score date Aug 18, 2026 · 99.8th percentile · first observed Aug 18, 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 Windows Domain Name System servers when they fail to properly handle requests, aka 'Windows DNS Server Remote Code Execution Vulnerability'.

Inspect raw assertion
Field
container
Value
A remote code execution vulnerability exists in Windows Domain Name System servers when they fail to properly handle requests, aka 'Windows DNS Server Remote Code Execution Vulnerability'.
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

Microsoft Windows DNS Server Remote Code Execution Vulnerability

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

91.35% probability · 99.8th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.913530000000; percentile 0.998030000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
6Underlying assertions
4Canonical products
6Target 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

8 scope groups

microsoft · source assertedMicrosoftWindows ServerDirect source scope
Affected: 2019Affected: 2019 (Core installation)Affected: 2016Affected: 2016 (Core installation)Affected: 2008 for 32-bit Systems Service Pack 2Affected: 2008 for 32-bit Systems Service Pack 2 (Core installation)Affected: 2008 for x64-based Systems Service Pack 2Affected: 2008 for x64-based Systems Service Pack 2 (Core installation)Affected: 2008 R2 for x64-based Systems Service Pack 1Affected: 2008 R2 for x64-based Systems Service Pack 1 (Core installation)Affected: 2012Affected: 2012 (Core installation)Affected: 2012 R2Affected: 2012 R2 (Core installation)
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "2019"}, {"status": "affected", "version": "2019 (Core installation)"}, {"status": "affected", "version": "2016"}, {"status": "affected", "version": "2016 (Core installation)"}, {"status": "affected", "version": "2008 for 32-bit Systems Service Pack 2"}, {"status": "affected", "version": "2008 for 32-bit Systems Service Pack 2 (Core installation)"}, {"status": "affected", "version": "2008 for x64-based Systems Service Pack 2"}, {"status": "affected", "version": "2008 for x64-based Systems Service Pack 2 (Core installation)"}, {"status": "affected", "version": "2008 R2 for x64-based Systems Service Pack 1"}, {"status": "affected", "version": "2008 R2 for x64-based Systems Service Pack 1 (Core installation)"}, {"status": "affected", "version": "2012"}, {"status": "affected", "version": "2012 (Core installation)"}, {"status": "affected", "version": "2012 R2"}, {"status": "affected", "version": "2012 R2 (Core installation)"}]
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"}]
microsoft · source assertedMicrosoftWindows Server, version 2004 (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_server_2008Vulnerable target · 2 assertions
Version not applicable; Version r2Canonical identity product-217b1ab3d25f361a639824f86753d418b35aa2a816ee370bb71b5d1dd883d87aLinked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    af07a81d-12e5-4b1d-bff9-c8d08c32ff4f
  2. cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    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
  1. cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 2
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    a7df96f8-ba6a-4780-9ca3-f719b3f81074
  2. cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 3
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    db18c4ce-5917-401e-acf7-2747084fd36e
NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_2016Vulnerable target · 1 assertions
Version not applicableCanonical identity product-02e254d111ce604757a15650ef469f4f8365d6247da82ce3ac2695c3cfc7dc5fLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_server_2016:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 4
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    041ff8ba-0b12-4a1f-b4bf-9c4f33b7c1e7
NVD CPE · OPERATING SYSTEMmicrosoftwindows_server_2019Vulnerable target · 1 assertions
Version not applicableCanonical identity product-25a2932c0bbcb648f7e391c8b9d34c734e5085444c03c1c206b9d4c4baa80b25Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:microsoft:windows_server_2019:-:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 5
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    db79ee26-fc32-417d-a49c-a1a63165a968

Affected-product evidence

Accepted scope and product mapping

4 canonical links · 1 source-reported links

Mapping establishedEvidence supported

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
705a5669-102d-455e-b215-0cfaf4d2237c
Mapping establishedEvidence supported

vendor-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
39a56e35-dc1e-4003-9231-cc6c66ccde1a53bf2fb8-982e-4501-a193-7d5adf5d0306
Mapping establishedEvidence supported

vendor-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
b0ebd47f-a125-4d28-a5ed-1ffdc0ff852f
Mapping establishedEvidence supported

vendor-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
59a8755d-a99f-4818-beef-5221dc827b02c85efd32-5d84-465f-ba3c-f5fb409f7000
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
4
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
2d8cfd45-9dfe-4ba0-9cb6-e17e9c534ae3a2eebbdb-0fc9-473d-8170-77a735844adca88d3146-a587-44e7-935a-fcf6eb5c3a9cb884a3ba-73ed-45de-be9d-bcb7864501fa

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
10.0
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:N/AC:L/Au:N/C:C/I:C/A:C
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.