CASCACascade Atlas

Evidence dossier

CVE-2023-35311

Microsoft Outlook Security Feature Bypass Vulnerability

Exploited in the wild (CISA KEV since Jul 11, 2023). secure@microsoft.com reports CVSS 3.1 8.8. Severity assessments differ within at least one CVSS version. EPSS estimates 15.5% exploit likelihood as of Oct 22, 2026.

66.6–80.2Priority evidence range
Evidence through Oct 22, 2026, 6:07 PM UTC

As of Oct 22, 2026

Normalized restatement

Microsoft Outlook Security Feature Bypass Vulnerability

State
PUBLISHED
Published
Jul 11, 2023
Updated
Oct 7, 2026
Evidence coverage
72%

Evidence chronology

What was known when

Download this view's receipt →
  1. Source dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Microsoft Outlook Security Feature Bypass Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Microsoft Outlook Security Feature Bypass Vulnerability
    Original evidence ↗
  2. 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 ↗
  3. 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 ↗
  4. Source dateSource date omittedFirst observed by CASCA
    microsoft

    Record text: Microsoft Outlook Security Feature Bypass Vulnerability

    Inspect raw assertion
    Field
    container
    Value
    Microsoft Outlook Security Feature Bypass Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 15.52% probability · 96.8th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.155220000000; percentile 0.968050000000
    Original evidence ↗

Assessments differ

secure@microsoft.com8.8CVSS 3.1 · source date omitted
NVD7.5CVSS 3.1 · source date omitted

Values are shown separately by source and CVSS version.

ExploitationCatalog member

CISA KEV · catalog date Jul 11, 2023 · first observed Sep 1, 2026

Exploit likelihood15.52%

FIRST EPSS · score date Oct 22, 2026 · 96.8th percentile · first observed Oct 22, 2026

SeverityAssessments differ

secure@microsoft.com · CVSS 3.1 · first observed Oct 8, 2026 · values shown separately below

Evidence detail

Source limits and decisions

Why each evidence state has this value

casca-unknown-reasons-v1
Exploitation statusLast verified source snapshot retained

The last verified source boundary remains in force for this claim.

Revision
evidence-policy-v1.1.0
Cutoff
Oct 22, 2026
Resolution
Review source contract
Exploit likelihoodEvidence supported

Eligible evidence is present for this bounded claim.

Revision
evidence-policy-v1.1.0
Cutoff
Oct 22, 2026
Resolution
None
Severity assessmentAssessments differ

Eligible assertions materially conflict and remain visible side by side.

Revision
casca-direct-cvss-eligibility-v1
Cutoff
Oct 22, 2026
Resolution
Resolve conflict
Affected productsSource-reported scope

The cited source assertion is retained while canonical product linkage remains open.

Revision
casca-factor-d-obligations-v1
Cutoff
Oct 22, 2026
Resolution
Resolve identity

Source comparison

Who said what

CISA KEVOriginal assertion
Exploitation cataloged

Microsoft Outlook Security Feature Bypass Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Microsoft Outlook Security Feature Bypass Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
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

Microsoft Outlook Security Feature Bypass Vulnerability

Inspect raw assertion
Field
container
Value
Microsoft Outlook Security Feature Bypass Vulnerability
Source dateSource date omittedFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

15.52% probability · 96.8th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.155220000000; percentile 0.968050000000
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

10 scope groups

microsoft · source assertedMicrosoftMicrosoft 365 Apps for EnterpriseDirect source scope
Affected: 16.0.1 to before https://aka.ms/OfficeSecurityReleases (custom comparison)
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "16.0.1", "lessThan": "https://aka.ms/OfficeSecurityReleases", "versionType": "custom"}]
microsoft · source assertedMicrosoftMicrosoft Office 2019Direct source scope
Affected: 19.0.0 to before https://aka.ms/OfficeSecurityReleases (custom comparison)
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "19.0.0", "lessThan": "https://aka.ms/OfficeSecurityReleases", "versionType": "custom"}]
microsoft · source assertedMicrosoftMicrosoft Office LTSC 2021Direct source scope
Affected: 16.0.1 to before https://aka.ms/OfficeSecurityReleases (custom comparison)
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "16.0.1", "lessThan": "https://aka.ms/OfficeSecurityReleases", "versionType": "custom"}]
microsoft · source assertedMicrosoftMicrosoft Outlook 2013Direct source scope
Affected: 14.0.0 to before 15.0.5571.1000 (custom comparison)
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "14.0.0", "lessThan": "15.0.5571.1000", "versionType": "custom"}]
microsoft · source assertedMicrosoftMicrosoft Outlook 2013 Service Pack 1Direct source scope
Affected: 15.0.0.0 to before 15.0.5571.1000 (custom comparison)
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "15.0.0.0", "lessThan": "15.0.5571.1000", "versionType": "custom"}]
microsoft · source assertedMicrosoftMicrosoft Outlook 2016Direct source scope
Affected: 16.0.0.0 to before 16.0.5404.1000 (custom comparison)
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "16.0.0.0", "lessThan": "16.0.5404.1000", "versionType": "custom"}]
NVD CPE · APPLICATIONmicrosoft365_appsVulnerable target · 1 assertions
Version not applicableCanonical identity product-14a59f3c1c4fc4cec4da9e1d602ac339da114e67c884352e121c41fb03b7a712Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    40c15edd-98d4-4d06-ba06-21ae0f33c72d
NVD CPE · APPLICATIONmicrosoftofficeVulnerable target · 1 assertions
Version 2019Canonical identity product-f4efee17050cd92d62299077c43827052b373ddcb783c02caa43c2fbb378d2f4Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:a:microsoft:office:2019:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    ff177984-a906-43fa-bf60-298133fbbd6b
NVD CPE · APPLICATIONmicrosoftoffice_long_term_servicing_channelVulnerable target · 1 assertions
Version 2021Canonical identity product-911e466d0be7cb2953297756c47cb44a2f472c517f89b133f4ff5b03a0ab5264Linked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 2
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    0b3ef1e5-4757-4cfa-ae72-6ba876d3c9fd
NVD CPE · APPLICATIONmicrosoftoutlookVulnerable target · 3 assertions
Version 2013; Version 2016Canonical identity product-b312c98eb5c91fc7c3e69712233ab82c14dbc3f5723b9932de5a535b454ad87cLinked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:a:microsoft:outlook:2013:-:-:*:-:-:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 3
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    77f369d5-6771-4141-a116-50fb275a937a
  2. cpe:2.3:a:microsoft:outlook:2013:sp1:*:*:rt:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 4
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    dda98a76-d0d1-4bfa-beac-1c2313f7b859
  3. cpe:2.3:a:microsoft:outlook:2016:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 5
    Logic
    OR
    Version bounds
    No explicit bounds
    Match ID
    e2b1657c-0ff4-461a-be2a-641275c4b0a0

Affected-product evidence

Accepted scope and product mapping

0 canonical links · 2 source-reported links

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
Oct 22, 2026
Retained assertion IDs
0da0bf9a-22eb-44de-bdf3-870ba4950106658e2aae-60e8-41c0-b3e2-627df46b9f869e327871-eb5b-433e-bde6-98f2c7539093c92a278a-0b9e-4704-873e-e73c39ccb5a5e1ceef14-7373-45b4-a5ea-250f5cd90f53ed6c4ff7-90c9-491c-b78b-de92d03740cc
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
Nvd cpe vulnerable target
Assertions
8
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Oct 22, 2026
Retained assertion IDs
1759a587-c26a-45d0-9392-2109a20bc43b5820c024-836a-4025-80d8-3828adb81c4f655278f3-b206-4871-a69c-cdac749140088988d18d-7481-4181-8e1d-74a8642ec686b7eb06d8-0460-4ac0-bcce-a989745bcd0ec022dc5b-759f-483b-9eec-b6b9d0e28973d4c2340b-8b0c-4ab2-93d8-6dd1d5bba544d76ce7a0-460a-4293-bde8-cb3adf03494d

Assessments

CVSS by origin

8.8
secure@microsoft.comCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
7.5
NVDCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
8.8
microsoftCVSS 3.1 · role unknown · display onlyDirect record assessment retained outside normalized eligibilityCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C

Direct CVE/CNA normalized decisions

8.8Priority eligible

microsoft

CVSS 3.1 · Primary · Original assertion · rank 1

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
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.