HIGHZero Day
Verified
Global

Apple Patches Actively Exploited WebKit Zero-Day in iOS and macOS

·Source: Apple / Citizen Lab

Updated:

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

Indicators of Compromise (1)

CVE (1)
CVE-2026-23529
NVDMITRE CVE
Source Attribution

Originally published by Apple / Citizen Lab on Feb 25, 2026. Verified by: Apple, Citizen Lab.

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