Is CVE-2020-9818 in the CISA KEV catalog?

Yes. CVE-2020-9818 is on the CISA Known Exploited Vulnerabilities list, added 2021-11-03.

What is the CVSS severity of CVE-2020-9818?

CVE-2020-9818 has a CVSS v3 base score of 8.8 (HIGH).

What is the EPSS score for CVE-2020-9818?

CVE-2020-9818 has an EPSS score of 2.29% (81th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2020-9818

HIGHCISA KEVEPSS 81th pctl

8.8

CVSS v3

NVD

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.

CWE-787Out-of-bounds Write

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionRequired

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Exploit Intelligence

2.29%probability of exploitation in 30 days

81stpercentile

Elevated risk: more likely to be exploited than 81% of all known CVEs.

Known Exploited Vulnerability (CISA KEV)

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

Apple iOS, iPadOS, and watchOS Mail contains an out-of-bounds write vulnerability which may allow memory modification or application termination when processing a maliciously crafted mail message.

Apply updates per vendor instructions.

Remediation due: 2022-05-03

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-10-23.