CVE-2020-9818

Name: CVE-2020-9818
Creator: NVD / NIST
Published: 2020-06-09T17:15:13.317+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10Actively ExploitedEPSS 2.29%

Last modified Jun 17, 2026

CVE-2020-9818 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. 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. CISA has confirmed active exploitation in the wild. EPSS estimates a 2.29% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

2.29%

81.0th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by May 3, 2022.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Apple	Ipados	< 13.5
Apple	Iphone Os	< 12.4.7
Apple	Iphone Os	>= 13.0, < 13.5
Apple	Watchos	< 6.2.5

References

https://support.apple.com/HT211168Release Notes, Vendor Advisory
https://support.apple.com/HT211169Release Notes, Vendor Advisory
https://support.apple.com/HT211175Release Notes, Vendor Advisory
https://support.apple.com/HT211168Release Notes, Vendor Advisory
https://support.apple.com/HT211169Release Notes, Vendor Advisory
https://support.apple.com/HT211175Release Notes, Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-9818US Government Resource

Timeline

Published: Jun 9, 2020
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2020-9818?

How severe is CVE-2020-9818?

CVE-2020-9818 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 2.29% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2020-9818?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-9818?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST