CASCACascade Atlas

Evidence dossier

CVE-2020-9818

CVE-2020-9818

60.0–80.0Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 13.5 and iPadOS 13.5, iOS 12.4.7, watchOS 6.2.5. Processing a maliciously crafted mail message may lead to unexpected memory modification or application termination.

State
PUBLISHED
Published
Jun 9, 2020
Updated
Dec 20, 2025
Evidence coverage
72%
CISA KEVCatalog member

Apply updates per vendor instructions.

FIRST EPSS2.29%

2026-07-18 · v2026.06.15 · percentile 81.2%

Source stateConflict visible

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

appleoriginal assertion
container

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 13.5 and iPadOS 13.5, iOS 12.4.7, watchOS 6.2.5. Processing a maliciously crafted mail message may lead to unexpected memory modification or application termination.

CISA-ADPindependent enrichment
container

CISA ADP Vulnrichment

CVEderivative copy
container

CVE Program Container

CISA KEVoriginal assertion
observed_exploitation

Apple iOS, iPadOS, and watchOS Out-of-Bounds Write Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.022860000000; percentile 0.812460000000

Applicability

Cited product scope

Trace impact →
AppleiOS
[{"status": "affected", "version": "unspecified", "lessThan": "iOS 13.5 and iPadOS 13.5", "versionType": "custom"}]unknown
AppleiOS-1
[{"status": "affected", "version": "unspecified", "lessThan": "iOS 12.4.7", "versionType": "custom"}]unknown
ApplewatchOS
[{"status": "affected", "version": "unspecified", "lessThan": "watchOS 6.2.5", "versionType": "custom"}]unknown
Unknown vendorUnknown product
cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*; end excluding 13.5supported
Unknown vendorUnknown product
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*; end excluding 12.4.7supported
Unknown vendorUnknown product
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*; start including 13.0; end excluding 13.5supported
Unknown vendorUnknown product
cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*; end excluding 6.2.5supported

Assessments

CVSS by origin

8.8
nvd@nist.govCVSS 3.1 · role PrimaryCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8
nvd@nist.govCVSS 2.0 · role PrimaryAV:N/AC:M/Au:N/C:P/I:P/A:P
8.8
134c704f-9b21-4f2e-91b3-4a467353bcc0CVSS 3.1 · role SecondaryCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.8
CISA-ADPCVSS 3.1 · role unknownCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Limitations and unknowns

  • 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; unresolved scope remains unknown.
  • NVD-carried upstream facts remain derivative and are not independent corroboration.
  • 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.
  • Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.