CVE-2021-1789: Apple Multiple Products Type Confusion Vulnerability

High severity, CVSS 8.8. Actively exploited: in CISA KEV since 2022-05-04. EPSS: 14% chance of exploitation in the next 30 days.

A type confusion issue was addressed with improved state handling. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4, Safari 14.0.3. Processing maliciously crafted web content may lead to arbitrary code execution.

Affected products

• Apple iPadOS: before 14.4 (fixed in 14.4)
• Apple iPhone OS: before 14.4 (fixed in 14.4)
• Apple Mac OS X: from 10.14, before 10.14.6 (fixed in 10.14.6); from 10.15, before 10.15.7 (fixed in 10.15.7); version 10.14.6 only; version 10.15.7 only
• Apple macOS: from 11.0, before 11.2 (fixed in 11.2)
• Apple tvOS: before 14.4 (fixed in 14.4)
• Apple watchOS: before 7.3 (fixed in 7.3)
• Fedoraproject Fedora: version 32 only; version 33 only
• WebKitGTK WebKitGTK: before 2.30.6 (fixed in 2.30.6)

Published 2021-04-02. Last modified 2026-06-17.