CVE-2026-43771 in macOS
Summary
by MITRE • 07/28/2026
A stack overflow was addressed with improved input validation. 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 a denial-of-service.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 07/28/2026
This vulnerability represents a classic stack overflow condition that was remediated through enhanced input validation measures. The flaw existed within the operating system's kernel or system-level components that process user inputs without adequate bounds checking, creating an exploitable condition where malformed data could overwrite adjacent memory locations on the call stack. Such vulnerabilities typically arise when developers fail to validate the size and content of input parameters before processing them in memory allocation operations. The remediation approach focused on strengthening input validation mechanisms to prevent buffer overflows from occurring in the first place.
The operational impact of this vulnerability extends beyond simple denial-of-service conditions, though that represents the primary concern. While the immediate effect was that an application could trigger a system crash or hang through controlled input manipulation, stack overflow conditions often provide potential pathways for more sophisticated attacks including privilege escalation and code execution. The fact that this affects multiple macOS versions from Sequoia through Tahoe indicates the vulnerability spans across a significant portion of the operating system's architecture, suggesting it was likely present in core system libraries or kernel components that handle various input processing scenarios.
The mitigation strategy implemented involves enhanced input validation which aligns with established security practices and addresses the underlying CWE-121 stack-based buffer overflow weakness. This approach prevents malicious inputs from exceeding allocated buffer boundaries by implementing stricter size checks, bounds verification, and proper memory management routines. The vulnerability's presence across multiple macOS versions demonstrates how such flaws can persist in system components for extended periods, highlighting the importance of regular security updates and patch management programs. Organizations should ensure immediate deployment of these patches to protect against potential exploitation attempts.
From an ATT&CK framework perspective, this vulnerability would map to techniques involving privilege escalation and denial-of-service attacks through system-level input manipulation. The remediation effort directly addresses the attack surface by eliminating the conditions that allow attackers to manipulate stack memory through crafted inputs. Security teams should monitor for any signs of exploitation attempts or unauthorized application behavior that might indicate successful exploitation of similar vulnerabilities in unpatched systems, particularly in environments where patch deployment cycles are extended.