Reference page — cumulative record through Wednesday, October 7, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2020-9818

CVE-2020-9818HIGH

Apple iOS, iPadOS, and watchOS

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   R  U  H  H  H    8.8   .0229   82.6   YES

AFFECTED
  Product  Versions       Fixed
  iOS      unspecified –  —
  iOS-1    unspecified –  —
  watchOS  unspecified –  —

TIMELINE
  Mar 2   Reserved by apple
  Jun 9   Published (CNA: apple)
  Nov 3   Added to CISA KEV, remediation due 2022-05-03

CWE-787 · CNA: apple · CVSS v3.1 · 4 references · KEV due May 3, 2022

Description

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
March 2, 2020	Reserved	Reserved by apple
June 9, 2020	Published	Published (CNA: apple)
November 3, 2021	KEV ADDED	Added to CISA KEV, remediation due 2022-05-03

Affected

Affected products and packages — 3 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
Apple	iOS	—	unspecified	—
Apple	iOS-1	—	unspecified	—
Apple	watchOS	—	unspecified	—

Weaknesses

CWE-787

References (4)

https://support.apple.com/HT211168 [x_refsource_MISC]
https://support.apple.com/HT211169 [x_refsource_MISC]
https://support.apple.com/HT211175 [x_refsource_MISC]
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-9818 [government-resource]

Authoritative record: CVE-2020-9818 at cve.org

Vendors: apple

Weaknesses: CWE-787

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2020-9818 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, October 7, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.