CVE-2018-4427: Apple iPhone OS

High severity, CVSS 7.8. EPSS: 1.1% chance of exploitation in the next 30 days.

A memory corruption issue was addressed with improved memory handling. This issue affected versions prior to: iOS 12.1, watchOS 5.1.2, tvOS 12.1.1, macOS High Sierra 10.13.6 Security Update 2018-003 High Sierra, macOS Sierra 10.12.6 Security Update 2018-006.

Affected products

• Apple iPhone OS: before 12.1 (fixed in 12.1)
• Apple Mac OS X: before 10.14.2 (fixed in 10.14.2)
• Apple tvOS: before 12.1.1 (fixed in 12.1.1)
• Apple watchOS: before 5.1.2 (fixed in 5.1.2)

Published 2019-04-03. Last modified 2026-06-17.