CVE-2026-43799 in iOS
Summary
by MITRE • 07/28/2026
A use after free issue was addressed with improved memory management. 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, 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
This vulnerability represents a classic use-after-free condition that was remediated through enhanced memory management mechanisms within Apple's operating systems. The flaw occurred when an application could potentially manipulate memory objects in such a way that they were freed from memory while still being referenced by other processes or threads, creating a scenario where subsequent access to the freed memory could trigger unpredictable behavior including system crashes or unexpected termination. Such vulnerabilities are particularly dangerous because they can be exploited to execute arbitrary code or cause denial of service conditions that compromise system stability and security.
The technical implementation of this use-after-free issue falls under the common weakness enumeration CWE-416 which specifically addresses "Use After Free" conditions where a program continues to reference memory after it has been freed by the system. This particular vulnerability was present across multiple Apple platforms including iOS, iPadOS, macOS variants, tvOS, visionOS, and watchOS, indicating a systemic memory management flaw that required coordinated patching across the entire ecosystem. The security implications extend beyond simple application crashes as these conditions can be leveraged by malicious actors to escalate privileges or execute unauthorized code within the system boundaries.
The operational impact of this vulnerability was significant given its potential to cause unexpected system termination which could result in data loss, service disruption, and user experience degradation. Applications that were able to trigger this condition could potentially crash system processes or even entire operating system components, leading to complete system instability. The fix implemented by Apple involved strengthening memory management routines to ensure proper object lifecycle handling and prevent scenarios where freed memory blocks could be accessed by subsequent operations.
Mitigation strategies for this vulnerability required immediate deployment of the security updates across all affected platforms as specified in the release notes. Organizations should prioritize patching their devices to iOS 26.6, iPadOS 26.6, macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6, tvOS 26.6, visionOS 26.6, and watchOS 26.6 to eliminate the risk of exploitation. The remediation approach aligns with ATT&CK technique T1059 which involves system compromise through code execution, but in this case represents a defensive measure to prevent such exploitation pathways from being available to adversaries. Security teams should monitor for any indicators of compromise related to unusual system termination patterns or application behavior that might suggest attempted exploitation of memory management vulnerabilities within their environments.
The resolution of this vulnerability demonstrates Apple's ongoing commitment to addressing memory safety issues through proactive security updates and improved runtime protections. The fix likely involved enhanced memory tracking mechanisms, stricter validation of object references, and additional sanitization checks that prevent the scenario where freed memory could be accessed by subsequent operations. This represents a fundamental improvement in how the operating systems handle memory deallocation and reclamation processes, reducing the attack surface for similar classes of vulnerabilities that could potentially lead to privilege escalation or arbitrary code execution attacks.