CVE-2021-30904: Apple macOS

Medium severity, CVSS 5.3. EPSS: 0.8% chance of exploitation in the next 30 days.

A sync issue was addressed with improved state validation. This issue is fixed in macOS Monterey 12.0.1. A user's messages may continue to sync after the user has signed out of iMessage.

Affected products

• Apple macOS: before 12.0.1 (fixed in 12.0.1)

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