CVE-2020-27911: Apple iCloud

High severity, CVSS 7.8. EPSS: 3.4% chance of exploitation in the next 30 days.

An integer overflow was addressed through improved input validation. This issue is fixed in macOS Big Sur 11.0.1, watchOS 7.1, iOS 14.2 and iPadOS 14.2, iCloud for Windows 11.5, tvOS 14.2, iTunes 12.11 for Windows. A remote attacker may be able to cause unexpected application termination or arbitrary code execution.

Affected products

• Apple iCloud: before 11.5 (fixed in 11.5)
• Apple iPadOS: before 14.2 (fixed in 14.2)
• Apple iPhone OS: before 14.2 (fixed in 14.2)
• Apple iTunes: before 12.11 (fixed in 12.11)
• Apple macOS: from 11.0, before 11.0.1 (fixed in 11.0.1)
• Apple tvOS: before 14.2 (fixed in 14.2)
• Apple watchOS: before 7.1 (fixed in 7.1)

Published 2020-12-08. Last modified 2026-06-17.