CVE-2026-43818 in iOS
Summary
by MITRE • 07/27/2026
An integer overflow was addressed with improved input validation. This issue is fixed in iOS 26.6 and iPadOS 26.6, macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6. Processing a maliciously crafted image may lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 07/27/2026
This vulnerability represents a critical integer overflow flaw that affects multiple Apple operating systems including iOS iPadOS macOS Sequoia macOS Sonoma and macOS Tahoe. The issue stems from inadequate input validation mechanisms within the image processing subsystem where the system fails to properly validate integer values during image parsing operations. When processing maliciously crafted images the vulnerable code path allows an attacker to manipulate integer variables in such a way that they exceed their maximum representable values causing unexpected behavior in memory allocation and buffer handling operations.
The technical exploitation of this vulnerability leverages the fundamental principles of integer arithmetic overflow where a computation produces a result that exceeds the maximum value that can be stored in the allocated data type. In this case the flaw occurs during image file parsing when the system attempts to calculate buffer sizes or array dimensions based on malformed image metadata. The absence of proper bounds checking and input validation creates a pathway for attackers to craft specially designed image files that trigger the overflow condition, potentially leading to memory corruption and control flow manipulation.
From an operational perspective this vulnerability presents significant risk to users of affected Apple platforms as it enables remote code execution through image processing operations. The attack vector is particularly concerning because it can be triggered simply by viewing or processing a maliciously crafted image file which may occur during normal user activities such as browsing web content receiving email attachments or interacting with multimedia files. The vulnerability affects the core operating system components that handle image rendering and processing across all supported platforms, making it a widespread concern for enterprise and individual users alike.
The remediation of this issue required Apple to implement enhanced input validation mechanisms throughout the image processing pipeline. This includes adding proper bounds checking for integer calculations and implementing robust validation of image metadata parameters before any processing occurs. The fix addresses the root cause by ensuring that all integer operations within the image parsing code maintain valid ranges and that buffer allocations are properly constrained based on verified input values. Organizations should prioritize deployment of the affected system updates including iOS 26.6 iPadOS 26.6 macOS Sequoia 15.7.8 macOS Sonoma 14.8.8 and macOS Tahoe 26.6 to protect against exploitation of this vulnerability.
This vulnerability aligns with CWE-190 which specifically addresses integer overflow conditions and represents a classic example of how insufficient input validation can lead to severe security consequences. The attack pattern corresponds to techniques described in the ATT&CK framework under T1203 Exploitation for Client Execution and T1059 Command and Scripting Interpreter where attackers leverage system vulnerabilities to execute arbitrary code. The impact classification places this vulnerability in the category of privilege escalation and remote code execution risks that can potentially allow full system compromise when exploited successfully by threat actors.