CASCACascade Atlas

Evidence dossier

CVE-2020-9819

A memory consumption issue was addressed with improved memory handling.

Exploited in the wild (CISA KEV since Nov 3, 2021). NVD reports CVSS 3.1 4.3. EPSS estimates 2.2% exploit likelihood as of Aug 27, 2026.

57.8–61.1Priority evidence range
Evidence current through Aug 27, 2026, 6:09 PM UTC

As of Aug 27, 2026

Normalized restatement

A memory consumption issue was addressed with improved memory handling. This issue is fixed in iOS 13.5 and iPadOS 13.5, iOS 12.4.7, watchOS 6.2.5, watchOS 5.3.7. Processing a maliciously crafted mail message may lead to heap corruption.

State
PUBLISHED
Published
Jun 9, 2020
Updated
Dec 20, 2025
Evidence coverage
93%

Evidence chronology

What was known when

Download this view's receipt →
  1. Source dateSource date omittedFirst observed by CASCA
    apple

    Record text: A memory consumption issue was addressed with improved memory handling. This issue is fixed in iOS 13.5 and iPadOS 13.5, iOS 12.4.7, watchOS 6.2.5, watchOS 5.3.7. Processing a maliciously crafted mail message may lead to heap corruption.

    Inspect raw assertion
    Field
    container
    Value
    A memory consumption issue was addressed with improved memory handling. This issue is fixed in iOS 13.5 and iPadOS 13.5, iOS 12.4.7, watchOS 6.2.5, watchOS 5.3.7. Processing a maliciously crafted mail message may lead to heap corruption.
    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 dateFirst observed by CASCA
    CISA KEV

    Exploitation cataloged: Apple iOS, iPadOS, and watchOS Memory Corruption Vulnerability

    Inspect raw assertion
    Field
    observed_exploitation
    Value
    Apple iOS, iPadOS, and watchOS Memory Corruption Vulnerability
    Original evidence ↗
  5. Source dateFirst observed by CASCA
    FIRST EPSS

    EPSS score: 2.18% probability · 81.02th percentile

    Inspect raw assertion
    Field
    model_probability
    Value
    Probability 0.021780000000; percentile 0.810200000000
    Original evidence ↗
ExploitationCatalog member

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

Exploit likelihood2.18%

FIRST EPSS · score date Aug 27, 2026 · 81th percentile · first observed Aug 27, 2026

SeverityCVSS 4.3

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

appleOriginal assertion
Record text

A memory consumption issue was addressed with improved memory handling. This issue is fixed in iOS 13.5 and iPadOS 13.5, iOS 12.4.7, watchOS 6.2.5, watchOS 5.3.7. Processing a maliciously crafted mail message may lead to heap corruption.

Inspect raw assertion
Field
container
Value
A memory consumption issue was addressed with improved memory handling. This issue is fixed in iOS 13.5 and iPadOS 13.5, iOS 12.4.7, watchOS 6.2.5, watchOS 5.3.7. Processing a maliciously crafted mail message may lead to heap corruption.
Source dateSource date omittedFirst 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 ↗
CISA KEVOriginal assertion
Exploitation cataloged

Apple iOS, iPadOS, and watchOS Memory Corruption Vulnerability

Inspect raw assertion
Field
observed_exploitation
Value
Apple iOS, iPadOS, and watchOS Memory Corruption Vulnerability
Source dateFirst observed by CASCAOriginal evidence ↗
FIRST EPSSOriginal assertion
EPSS score

2.18% probability · 81.02th percentile

Inspect raw assertion
Field
model_probability
Value
Probability 0.021780000000; percentile 0.810200000000
Source dateFirst observed by CASCAOriginal evidence ↗

Applicability

Cited product scope

Trace impact →
5Underlying assertions
3Canonical products
5Target 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

apple · source assertedAppleiOSDirect source scope
Affected: unspecified to before iOS 13.5 and iPadOS 13.5 (custom comparison)
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "unspecified", "lessThan": "iOS 13.5 and iPadOS 13.5", "versionType": "custom"}]
apple · source assertedAppleiOS-1Direct source scope
Affected: unspecified to before iOS 12.4.7 (custom comparison)
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "unspecified", "lessThan": "iOS 12.4.7", "versionType": "custom"}]
apple · source assertedApplewatchOSDirect source scope
Affected: unspecified to before watchOS 6.2.5 (custom comparison)
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "unspecified", "lessThan": "watchOS 6.2.5", "versionType": "custom"}]
apple · source assertedApplewatchOS-1Direct source scope
Affected: unspecified to before watchOS 5.3.7 (custom comparison)
Source-reported scope

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

Inspect raw assertion[{"status": "affected", "version": "unspecified", "lessThan": "watchOS 5.3.7", "versionType": "custom"}]
NVD CPE · OPERATING SYSTEMappleipadosVulnerable target · 1 assertions
Any version (unconstrained) (< 13.5)Canonical identity product-8e7094ac066248cd4828b6ec8e3a96d010ed1c68f6083af46638775d737da0adLinked exact
Scope supported
Inspect raw assertion
  1. cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 0
    Logic
    OR
    Version bounds
    through excluding 13.5
    Match ID
    9145c3cb-429b-4fb8-a0ac-b543e9fff938
NVD CPE · OPERATING SYSTEMappleiphone_osVulnerable target · 2 assertions
Any version (unconstrained) (< 12.4.7); Any version (unconstrained) (>= 13.0, < 13.5)Canonical identity product-665d7155d02581979844685e7fca6c2680af997f9200af455887b1c71c483272Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 1
    Logic
    OR
    Version bounds
    through excluding 12.4.7
    Match ID
    0acd1157-ad87-4487-897f-009fc3204a2a
  2. cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 2
    Logic
    OR
    Version bounds
    from including 13.0; through excluding 13.5
    Match ID
    05af2126-2012-4a6a-bf40-2870d87c85d8
NVD CPE · OPERATING SYSTEMapplewatchosVulnerable target · 2 assertions
Any version (unconstrained) (< 5.3.7); Any version (unconstrained) (>= 6.0.0, < 6.2.5)Canonical identity product-1b28e85eba5cb27cd93d563b4ea63a555b916484cee543c65fdbe57d529fc0d1Linked exact
Scope supported
Inspect raw assertions
  1. cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 4
    Logic
    OR
    Version bounds
    from including 6.0.0; through excluding 6.2.5
    Match ID
    4958b539-a747-4bcc-acad-caa119ef7e64
  2. cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*
    Official link
    Linked exact
    Role
    Vulnerable target
    Configuration
    0 · node/0 · match 3
    Logic
    OR
    Version bounds
    through excluding 5.3.7
    Match ID
    3ec6365f-4e95-46f1-9ffd-e41bc8bfeaaa

Affected-product evidence

Accepted scope and product mapping

3 canonical links · 1 source-reported links

Mapping establishedEvidence supported

vendor-d6ed6f1e35de2e16a8a10f2ae364dab009bb2afadd609071b20da24d60ce2829 · product-1b28e85eba5cb27cd93d563b4ea63a555b916484cee543c65fdbe57d529fc0d1

Source class
Nvd cpe vulnerable target
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
35789ade-3300-4a7d-ba6d-c0c0a612161eab37158a-2143-4bbd-af8c-288494199d07
Mapping establishedEvidence supported

vendor-d6ed6f1e35de2e16a8a10f2ae364dab009bb2afadd609071b20da24d60ce2829 · product-665d7155d02581979844685e7fca6c2680af997f9200af455887b1c71c483272

Source class
Nvd cpe vulnerable target
Assertions
2
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
4049d864-430c-45ad-9c89-077a9dc7e70d43abe125-9edb-4239-8903-491db5ba577d
Mapping establishedEvidence supported

vendor-d6ed6f1e35de2e16a8a10f2ae364dab009bb2afadd609071b20da24d60ce2829 · product-8e7094ac066248cd4828b6ec8e3a96d010ed1c68f6083af46638775d737da0ad

Source class
Nvd cpe vulnerable target
Assertions
1
Mapping revision
cpe23-exact-mapping-v1
Observed cutoff
Aug 27, 2026
Retained assertion IDs
5e2949c2-1724-45a5-951b-2a1cc4dd10b2
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
26c5be6c-5292-4043-9de4-ba1bc289948e88d2f711-793a-4c42-8539-fc8f167db26f91e94718-eb62-4176-a311-a728cab40f45e6414c2e-f636-4bd1-a4e9-0c6f1e3eef85

Assessments

CVSS by origin

4.3
NVDCVSS 3.1 · role Primary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
4.3
NVDCVSS 2.0 · role Primary · priority eligiblevalid_matchAV:N/AC:M/Au:N/C:N/I:N/A:P
4.3
CVE Program sourceCVSS 3.1 · role Secondary · priority eligiblevalid_matchCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
4.3
CISA-ADPCVSS 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:N/I:N/A:L

Direct CVE/CNA normalized decisions

4.3Priority eligible

CISA-ADP

CVSS 3.1 · Secondary · Independent enrichment · rank 2

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
Validation
Valid match
Recomputed
4.3
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.