CVE-2018-4378: Apple iCloud

High severity, CVSS 8.8. EPSS: 1.5% chance of exploitation in the next 30 days.

A memory corruption issue was addressed with improved validation. This issue affected versions prior to iOS 12.1, tvOS 12.1, watchOS 5.1, Safari 12.0.1, iTunes 12.9.1, iCloud for Windows 7.8.

Affected products

• Apple iCloud: before 7.8 (fixed in 7.8)
• Apple iPhone OS: before 12.1 (fixed in 12.1)
• Apple iTunes: before 12.9.1 (fixed in 12.9.1)
• Apple Safari: before 12.0.1 (fixed in 12.0.1)
• Apple tvOS: before 12.1 (fixed in 12.1)
• Apple watchOS: before 5.1 (fixed in 5.1)

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