CVE-2021-1855: Apple macOS

Medium severity, CVSS 6.5. EPSS: 0.8% chance of exploitation in the next 30 days.

A logic issue was addressed with improved state management. This issue is fixed in macOS Big Sur 11.3. A malicious website may be able to force unnecessary network connections to fetch its favicon.

Affected products

• Apple macOS: from 11.0, before 11.3 (fixed in 11.3)

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