CASCACascade Atlas

Evidence dossier

CVE-2020-0688

A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory…

Exploited in the wild (CISA KEV since Nov 3, 2021). NVD reports CVSS 3.1 8.8. EPSS estimates 100.0% exploit likelihood as of Aug 26, 2026.

84.6–89.9Priority 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 Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory Corruption Vulnerability'.

State
PUBLISHED
Published
Feb 11, 2020
Updated
Oct 21, 2025
Evidence coverage
92%

Evidence chronology

What was known when

Download this view's receipt →
  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 Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory Corruption Vulnerability'.

    Inspect raw assertion
    Field
    container
    Value
    A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory Corruption Vulnerability'.
    Original evidence ↗
  4. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Microsoft Exchange Server Validation Key Remote Code Execution Vulnerability

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

    EPSS score: 99.97% probability · 99.98th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.999650000000; percentile 0.999760000000
    Original evidence ↗
ExploitationCatalog member

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

Exploit likelihood99.97%

FIRST EPSS · score date Aug 26, 2026 · 100th percentile · first observed Aug 26, 2026

SeverityCVSS 8.8

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 Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory Corruption Vulnerability'.

Inspect raw assertion
Field
container
Value
A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory Corruption Vulnerability'.
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
CISA KEVOriginal assertion
Exploitation cataloged

Microsoft Exchange Server Validation Key Remote Code Execution Vulnerability

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

99.97% probability · 99.98th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.999650000000; percentile 0.999760000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
6Underlying assertions
1Canonical 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

7 scope groups

microsoft · source assertedMicrosoftMicrosoft Exchange Server 2010 Service Pack 3 Update Rollup 30Direct 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 assertedMicrosoftMicrosoft Exchange Server 2013Direct source scope
Affected: Cumulative Update 23
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "Cumulative Update 23"}]
microsoft · source assertedMicrosoftMicrosoft Exchange Server 2016 Cumulative Update 14Direct 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 assertedMicrosoftMicrosoft Exchange Server 2016 Cumulative Update 15Direct 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 assertedMicrosoftMicrosoft Exchange Server 2019 Cumulative Update 3Direct 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 assertedMicrosoftMicrosoft Exchange Server 2019 Cumulative Update 4Direct 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 · APPLICATIONmicrosoftexchange_serverVulnerable target · 6 assertions
Version 2010; Version 2013; Version 2016; Version 2019Canonical identity product-d87daca995d075bf30565cc429e7242a47683272975068df1d327ec1d8ff609cLinked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_15:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 3
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    ca2ce223-aa49-49e6-ac32-59270eff55ad
  2. cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    da166f2a-d83b-4d50-ad0b-668d813e0585
  3. cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_14:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 2
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    55284cf7-0d04-4216-83fe-4b1f9ca94207
  4. cpe:2.3:a:microsoft:exchange_server:2010:sp3_rollup_30:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    276776e0-f9da-4f18-a984-5e7811465b80
  5. cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_3:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 4
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    104f96dc-e280-4e0a-8586-b043b55888c2
  6. cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_4:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 5
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    73b3b3fe-7e85-4b86-a983-2c410ffef4b8

Affected-product evidence

Accepted scope and product mapping

1 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-01299a5a765aea70faa05f2d06e0c26a5d498fd34553e868d89e8a43b31864db · product-d87daca995d075bf30565cc429e7242a47683272975068df1d327ec1d8ff609c

Source class
Nvd cpe vulnerable target
Assertions
6
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
38630b72-77c5-46a4-8564-4d4fafe1753652c17383-c02f-41b8-8a8c-0413990434ddb5cccf44-7d7b-4493-9d44-b07ede59a256b6b5f1d4-434d-4a15-b789-d386bfd0f8ace5e8abd5-7612-409a-8292-8a122e3a3159f63fd744-8678-4106-ace9-a9bbac18ac3e
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
6
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
31916341-8753-45d1-9058-0570e74536973434c9dc-923a-43e7-b16e-580e8667f08a7c12e56d-5af2-49ac-93f1-a690fe909a80c51f92af-2f49-48a9-9964-aabc10747f75cbaeba85-f97a-454b-839b-f9ec989dea5bcc6108e7-bc81-428c-bf65-f91d21d6d213

Assessments

CVSS by origin

8.8
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
9.0
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:N/AC:L/Au:S/C:C/I:C/A:C
8.8
CVE Program sourceCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8
CISA-ADPCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Direct CVE/CNA normalized decisions

8.8Priority eligible

CISA-ADP

CVSS 3.1 · Secondary · Independent enrichment · rank 2

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Validation
Valid match
Recomputed
8.8
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.