CVE-2021-30901: Apple Mac OS X

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

Multiple out-of-bounds write issues were addressed with improved bounds checking. This issue is fixed in macOS Monterey 12.0.1, Security Update 2021-007 Catalina, macOS Big Sur 11.6.1. A malicious application may be able to execute arbitrary code with kernel privileges.

Affected products

• Apple Mac OS X: before 10.15.7 (fixed in 10.15.7); version 10.15.7 only
• Apple macOS: from 11.0, before 11.6.1 (fixed in 11.6.1); version 12.0 only

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