CVE-2020-3877: Apple Mac OS X

High severity, CVSS 7.5. EPSS: 2% chance of exploitation in the next 30 days.

An out-of-bounds read was addressed with improved input validation. This issue is fixed in macOS Catalina 10.15.3, watchOS 6.1.2. A remote attacker may be able to cause unexpected application termination or arbitrary code execution.

Affected products

• Apple Mac OS X: before 10.15.3 (fixed in 10.15.3)
• Apple watchOS: before 6.1.2 (fixed in 6.1.2)

Published 2020-02-27. Last modified 2026-06-17.