CVE-2021-1841: Apple Mac OS X

High severity, CVSS 7.8. EPSS: 1.3% chance of exploitation in the next 30 days.

A malicious application may be able to execute arbitrary code with kernel privileges. This issue is fixed in macOS Big Sur 11.3, Security Update 2021-002 Catalina. An out-of-bounds write issue was addressed with improved bounds checking.

Affected products

• Apple Mac OS X: version 10.14 only; version 10.14.0 only; version 10.14.1 only; version 10.14.2 only; version 10.14.3 only; version 10.14.4 only; …
• Apple macOS: from 11.0, before 11.3 (fixed in 11.3)

Published 2021-09-08. Last modified 2026-06-17.