CVE-2021-30900: Apple iOS, iPadOS, and macOS Out-of-Bounds Write Vulnerability

High severity, CVSS 7.8. Actively exploited: in CISA KEV since 2023-03-30. EPSS: 5.2% chance of exploitation in the next 30 days.

An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 14.8.1 and iPadOS 14.8.1, iOS 15.1 and iPadOS 15.1. A malicious application may be able to execute arbitrary code with kernel privileges.

Affected products

• Apple iPadOS: before 14.8.1 (fixed in 14.8.1); version 15.0 only
• Apple iPhone OS: before 14.8.1 (fixed in 14.8.1); version 15.0 only
• Apple macOS: before 11.6.1 (fixed in 11.6.1)

Published 2021-08-24. Last modified 2026-06-17.