HIGHZero Day
Verified
Global
Apple Patches Actively Exploited WebKit Zero-Day in iOS and macOS
Wednesday, February 25, 2026 at 06:00 PM UTC·Source: Apple / Citizen Lab
Updated: Thursday, February 26, 2026 at 10:00 AM UTC
Executive Summary
Apple releases emergency updates for iOS 18.4 and macOS 15.4 to fix WebKit zero-day used in targeted attacks. Sophisticated exploit chain confirmed.
Analysis
Apple has released emergency security updates for CVE-2026-23529, a use-after-free vulnerability in WebKit being actively exploited in "extremely sophisticated" targeted attacks. The vulnerability affects iOS, iPadOS, macOS, visionOS, and Safari. Apple credits Citizen Lab for the discovery, suggesting surveillance-related exploitation. Update to iOS 18.4, macOS 15.4, and Safari 18.4 immediately.
Timeline
Discovered
Feb 20, 2026
Exploitation Detected
Feb 20, 2026
Published
Feb 25, 2026
Patch Available
Feb 25, 2026