CVE-2026-20644
📋 TL;DR
This memory handling vulnerability in Apple's WebKit browser engine allows processing malicious web content to cause unexpected process crashes. It affects users of macOS, iOS, iPadOS, visionOS, and Safari who haven't updated to the patched versions. Attackers could exploit this to crash browsers or potentially execute arbitrary code.
💻 Affected Systems
- macOS
- iOS
- iPadOS
- visionOS
- Safari
📦 What is this software?
Ipados by Apple
Ipados by Apple
Macos by Apple
macOS is Apple's desktop and laptop operating system powering Mac computers used by millions of professionals, developers, creative professionals, and enterprise users worldwide. Built on a Unix foundation with the Darwin kernel and modern Cocoa frameworks, macOS delivers a seamless ecosystem integr...
Learn more about Macos →Safari by Apple
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to full system compromise if memory corruption is leveraged for arbitrary code execution
Likely Case
Denial of service through browser/application crashes when processing malicious web content
If Mitigated
No impact if systems are patched to the fixed versions
🎯 Exploit Status
Exploitation requires user to visit malicious website or process malicious web content; no authentication required
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: macOS Tahoe 26.3, iOS 18.7.5 and iPadOS 18.7.5, visionOS 26.3, iOS 26.3 and iPadOS 26.3, Safari 26.3
Vendor Advisory: https://support.apple.com/en-us/126346
Restart Required: Yes
Instructions:
1. Go to System Settings > General > Software Update. 2. Install available updates. 3. Restart device when prompted. For Safari: Update through App Store or system updates.
🔧 Temporary Workarounds
Disable JavaScript
macOSTemporarily disable JavaScript in Safari to reduce attack surface while waiting for patch
Safari > Settings > Security > uncheck 'Enable JavaScript'
Use alternative browser
allUse non-WebKit based browsers until systems can be patched
🧯 If You Can't Patch
- Implement web content filtering to block known malicious sites
- Restrict browser usage to trusted websites only
🔍 How to Verify
Check if Vulnerable:
Check current OS version against affected versions listCheck Version:
macOS: 'sw_vers', iOS/iPadOS: Settings > General > About, Safari: Safari > About SafariVerify Fix Applied:
Verify OS/browser version matches or exceeds patched versions📡 Detection & Monitoring
Log Indicators:
- Unexpected Safari/WebKit process crashes
- Kernel panic logs related to WebKit
Network Indicators:
- Multiple connections to suspicious domains followed by browser crashes
SIEM Query:
source="apple_system_logs" AND (process="Safari" OR process="WebKit") AND event="crash"