CVE-2026-43802 in macOS
Summary
by MITRE • 07/28/2026
An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6. An app may be able to cause unexpected system termination.
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Analysis
by VulDB Data Team • 07/28/2026
This vulnerability represents a classic out-of-bounds write condition that was remediated through enhanced bounds checking mechanisms within Apple's operating system kernel and system libraries. The flaw existed in the memory management subsystem where applications could potentially bypass proper boundary validation during data writes to allocated memory regions, leading to unauthorized memory corruption. Such issues typically arise when developers fail to properly validate array indices or buffer sizes before performing write operations, creating opportunities for malicious code execution or system instability.
The technical implementation of this vulnerability stems from insufficient input validation within system-level components responsible for memory allocation and deallocation processes. When applications attempt to write data beyond the allocated memory boundaries, they can overwrite adjacent memory locations containing critical system structures, function pointers, or control data. This type of flaw aligns with CWE-787: "Out-of-bounds Write" which specifically addresses conditions where programs write to memory locations outside the bounds of allocated buffers. The vulnerability could be exploited through crafted input or malicious applications that manipulate memory access patterns to trigger the out-of-bounds condition.
The operational impact of this vulnerability extends beyond simple system crashes or unexpected terminations, as it creates potential attack vectors for privilege escalation and persistent system compromise. When an application causes unexpected system termination, it may indicate that the compromised memory region contained critical kernel data structures or process control information. Attackers could potentially leverage such conditions to execute arbitrary code with elevated privileges, particularly if they can manipulate memory layout or predict address spaces during exploitation attempts. This scenario aligns with ATT&CK technique T1068: "Exploitation for Privilege Escalation" where initial access leads to system-level control through kernel vulnerabilities.
The remediation implemented by Apple through macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, and macOS Tahoe 26.6 demonstrates the importance of comprehensive bounds checking mechanisms in modern operating systems. These updates likely included enhanced memory validation routines that verify all memory write operations against allocated buffer boundaries before allowing data to be written. The fixes typically involve runtime checks that monitor array indices, buffer sizes, and memory access patterns to prevent unauthorized writes to protected system regions. System administrators should prioritize these updates as they address fundamental memory safety issues that could enable sophisticated attacks including kernel exploits and persistent backdoor installations.
Security professionals should consider this vulnerability within the broader context of memory safety vulnerabilities that have historically led to critical system compromises across multiple operating systems. The remediation approach taken by Apple reflects industry best practices for preventing buffer overflow conditions through automated bounds checking, stack canaries, and address space layout randomization techniques. Organizations should implement comprehensive patch management strategies to ensure all affected systems receive these critical updates promptly, as the window of opportunity for exploitation exists between initial vulnerability disclosure and system patching. The vulnerability underscores the necessity of continuous security monitoring and regular system updates to maintain operational resilience against evolving threat landscapes.