CVE-2026-84635 in iOS
Summary
by MITRE • 09/15/2026
A logic issue was addressed with improved state management. This issue is fixed in Safari 27, iOS 27 and iPadOS 27, macOS Golden Gate 27, tvOS 27, visionOS 27, watchOS 27. Processing maliciously crafted web content may lead to an unexpected process termination.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability described involves a logic error within the state management mechanisms of Apple's WebKit engine, which powers Safari and other browser-based applications across its ecosystem including iOS, iPadOS, macOS, tvOS, visionOS, and watchOS. This issue stems from improper handling of internal states during the processing of web content, specifically when encountering maliciously crafted inputs that exploit race conditions or inconsistent state transitions. The core technical flaw lies in the failure to properly validate or synchronize application states before executing subsequent operations, leading to a breakdown in expected program flow. Such logic errors are particularly dangerous because they often bypass standard input validation checks by relying on specific sequences of events rather than malformed data structures alone.
From a classification perspective, this vulnerability aligns with CWE-841 Improper Enforcement of Behavioral Workflow and potentially CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization if the issue involves multi-threaded state access. In terms of offensive security frameworks like MITRE ATT&CK, this type of flaw can be leveraged for Denial of Service (DoS) attacks under techniques such as T1499 Endpoint Denial of Service or potentially as a precursor to more complex exploits by destabilizing the browser process environment. The lack of robust state validation allows an attacker to trigger undefined behavior within the rendering engine, which manifests as unexpected process termination rather than arbitrary code execution in this specific instance.
The operational impact of this vulnerability is primarily characterized by service disruption and potential instability for end-users. When a user visits a maliciously crafted webpage or interacts with compromised web content, the browser may crash unexpectedly due to the corrupted state. This results in data loss if unsaved work was present in tabs that are terminated abruptly. Furthermore, frequent crashes can degrade system performance as resources must be reallocated and processes restarted by the operating system's watchdog mechanisms. While immediate remote code execution is not indicated, repeated exploitation could facilitate denial-of-service conditions against devices running affected versions of Safari or WebKit-based applications on Apple platforms.
Mitigation strategies focus heavily on software updates provided by Apple. Users should ensure their devices are updated to Safari 27, iOS 27, iPadOS 27, macOS Golden Gate 27, tvOS 27, visionOS 27, or watchOS 27 where the fix is implemented. For developers and security teams monitoring these environments, it is advisable to implement content security policies that restrict execution of untrusted scripts and utilize browser sandboxing features effectively. Additionally, deploying endpoint detection and response solutions capable of identifying abnormal process termination patterns in web browsers can help detect potential exploitation attempts before they cause significant disruption. Regular patch management remains the most effective defense against such logic-based vulnerabilities until deeper architectural changes to state handling are adopted by vendors.