CVE-2026-43731 in Safari
Summary
by MITRE • 06/30/2026
A use-after-free issue was addressed with improved memory management. This issue is fixed in Safari 26.5.2, iOS 26.5.2 and iPadOS 26.5.2, macOS Tahoe 26.5.2. Processing maliciously crafted web content may lead to memory corruption.
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Analysis
by VulDB Data Team • 06/30/2026
This vulnerability represents a classic use-after-free condition that was successfully addressed through enhanced memory management protocols within Apple's Safari browser and related operating systems. The flaw occurred when the browser processed maliciously crafted web content, creating a scenario where freed memory locations could be accessed or reused before proper deallocation, leading to potential memory corruption. Such vulnerabilities are particularly dangerous because they can be exploited by attackers to execute arbitrary code or cause unexpected application behavior. The issue was resolved in Safari version 26.5.2 along with corresponding updates for iOS 26.5.2, iPadOS 26.5.2, and macOS Tahoe 26.5.2, demonstrating Apple's proactive approach to addressing memory safety concerns in their web browser ecosystem.
The technical implementation of this vulnerability falls under the common weakness enumeration CWE-416, which specifically addresses use-after-free conditions where software continues to reference memory after it has been freed by the system or application. This particular flaw represents a sophisticated attack vector that leverages the complex memory management systems inherent in modern web browsers. When processing malicious web content, the browser's JavaScript engine or rendering components would trigger the use-after-free condition, potentially allowing attackers to manipulate memory contents and gain unauthorized access to system resources. The vulnerability could be exploited through various attack vectors including malicious websites, email attachments containing crafted web content, or compromised web applications that deliver the malicious payload directly to the browser environment.
From an operational impact perspective, this vulnerability presented a significant risk to users of affected Safari versions, as it could enable remote code execution attacks without requiring user interaction beyond visiting a malicious website. The memory corruption resulting from improper memory management could lead to application crashes, data loss, or more severe security breaches depending on the specific exploitation technique employed by threat actors. Organizations relying on Safari-based applications for web browsing and content delivery would have been particularly vulnerable during the window when this flaw existed in their systems. The attack surface was further expanded due to Safari's widespread use across Apple's ecosystem, including mobile devices, tablets, and desktop computers.
The mitigation strategy implemented by Apple focused on strengthening memory management protocols within the browser's core components, specifically addressing how freed memory blocks are handled during web content processing. This approach aligns with established cybersecurity practices for preventing use-after-free vulnerabilities, which typically involve implementing proper reference counting, null pointer checks, or employing memory sanitization techniques. The fix demonstrates the importance of regular security updates and patch management in maintaining browser security, as well as the necessity of continuous monitoring for memory safety issues in complex software systems. Organizations should ensure their Safari installations are updated to version 26.5.2 or later to prevent exploitation of this vulnerability, which could otherwise provide attackers with persistent access to affected systems through web-based attack vectors.