What’s Vulnerable › Vulnerabilities

CVE-2020-9818: Apple iOS, iPadOS, and watchOS Out-of-Bounds Write Vulnerability

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: yes — in CISA KEV since 2021-11-03
• EPSS: 2.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-06-09 · updated 2026-06-17
• Weakness: CWE-787

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.

Affected products

• Apple iPadOS: before 13.5 — fixed in 13.5
• Apple Iphone Os: before 12.4.7; from 13.0 before 13.5 — fixed in 12.4.7, 13.5
• Apple watchOS: before 6.2.5 — fixed in 6.2.5

How to fix

Upgrade to a fixed version: Apple iPadOS 13.5; Apple Iphone Os 12.4.7, 13.5; Apple watchOS 6.2.5. Check the vendor advisory for mitigations.

References

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

Get alerted when CVE-2020-9818 or the next vulnerability affects your stack