CVE-2026-43817 in iOS
Summary
by MITRE • 07/28/2026
An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in iOS 26.6 and iPadOS 26.6, macOS Tahoe 26.6, tvOS 26.6, visionOS 26.6, watchOS 26.6. An app may be able to cause unexpected system termination.
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Analysis
by VulDB Data Team • 07/28/2026
An out-of-bounds read vulnerability represents a critical memory safety issue that occurs when a program attempts to access memory locations outside the bounds of allocated buffers or arrays. This type of flaw falls under the common weakness enumeration CWE-125 which specifically addresses out-of-bounds read conditions in software applications. The vulnerability manifests when an application fails to properly validate array indices or buffer boundaries before accessing memory, potentially allowing malicious code to read data from adjacent memory locations. Such issues are particularly dangerous because they can expose sensitive information stored in memory, including cryptographic keys, user credentials, or system configuration details that should remain protected.
The technical implementation of this vulnerability involves improper bounds checking mechanisms within the affected software components. When an application processes input data or iterates through arrays without adequate validation, it creates opportunities for attackers to manipulate memory access patterns. The fix implemented in iOS 26.6, iPadOS 26.6, macOS Tahoe 26.6, tvOS 26.6, visionOS 26.6, and watchOS 26.6 demonstrates the importance of robust input validation and memory management practices. These updates address the specific scenario where an app could cause unexpected system termination by triggering memory access violations that lead to application crashes or system instability.
From an operational perspective, this vulnerability poses significant risks to system integrity and user data protection. The potential for unexpected system termination represents a denial-of-service condition that can disrupt normal device operations and potentially provide attackers with opportunities for further exploitation. According to the attack technique framework, this issue aligns with ATT&CK tactic TA0040 (defense evasion) and may enable subsequent attacks through system instability or information disclosure. The vulnerability's impact is particularly concerning in mobile environments where devices handle sensitive personal data and maintain persistent connections to various services.
The mitigation strategies for this vulnerability encompass multiple layers of protection including immediate deployment of the security updates, implementation of additional runtime checks, and enhanced code review processes for memory management operations. Organizations should prioritize patching affected systems to prevent exploitation while implementing monitoring mechanisms to detect anomalous behavior patterns that might indicate attempted exploitation. The fix represents a fundamental improvement in bounds checking that prevents unauthorized memory access while maintaining system stability and preventing the potential for more severe security consequences such as arbitrary code execution or privilege escalation attacks.