CVE-2026-43776 in iOS
Summary
by MITRE • 07/28/2026
A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 26.6 and iPadOS 26.6, macOS Sequoia 15.7.8, macOS Tahoe 26.6. Processing a maliciously crafted file may lead to unexpected app termination or arbitrary code execution.
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Analysis
by VulDB Data Team • 07/28/2026
This vulnerability represents a classic buffer overflow condition that was resolved through enhanced bounds checking mechanisms within Apple's operating systems. The flaw existed in the file processing routines where insufficient input validation allowed attackers to craft malicious files that could trigger memory corruption when parsed by affected applications. Such buffer overflows typically occur when programs write more data to a fixed-length buffer than it can accommodate, creating potential entry points for exploitation.
The technical implementation of this vulnerability aligns with common software security weaknesses documented in CWE-121 and CWE-122 categories, which specifically address stack-based and heap-based buffer overflow conditions. Attackers could exploit this weakness by preparing specially crafted files that, when processed by vulnerable applications, would cause the program to overwrite adjacent memory locations. This memory corruption could manifest as unexpected application termination or more critically, provide attackers with opportunities to execute arbitrary code within the context of the affected process.
The operational impact of this vulnerability extends beyond simple application instability to potentially enable full system compromise. When an application crashes due to buffer overflow exploitation, it may leave behind memory segments that could be leveraged for privilege escalation or persistent access. The fix implemented by Apple through enhanced bounds checking represents a defensive programming approach that validates input lengths against allocated buffer sizes, preventing the overwrite conditions that lead to exploitation.
Organizations should prioritize immediate deployment of the patched versions including iOS 26.6, iPadOS 26.6, macOS Sequoia 15.7.8, and macOS Tahoe 26.6 to mitigate potential exploitation attempts. The remediation addresses the root cause through improved input validation rather than relying on exploit mitigation techniques like stack canaries or address space layout randomization. Security teams should monitor for indicators of compromise related to this vulnerability, particularly unusual application crashes or unexpected memory access patterns in affected systems.
From an ATT&CK framework perspective, this vulnerability maps to technique T1059.007 for command and scripting interpreter execution through malicious file processing, and potentially T1203 for exploitation for privilege escalation if the vulnerable applications run with elevated privileges. The mitigation strategy should include comprehensive patch management across all affected platforms, along with monitoring for anomalous file processing behavior that could indicate exploitation attempts. Network-based detection systems should be updated to identify potential malicious file delivery attempts targeting this specific buffer overflow condition.
The vulnerability demonstrates how seemingly simple input validation issues can create significant security risks in operating system components, emphasizing the importance of secure coding practices and regular security assessments. The fix implementation shows Apple's commitment to addressing memory safety vulnerabilities through proactive code review and enhanced runtime protections that prevent the exploitation patterns associated with classic buffer overflow attacks.