CVE-2026-86904 in iOS
Summary
by MITRE • 09/15/2026
A privacy issue was addressed with improved state management. This issue is fixed in iOS 26.7 and iPadOS 26.7, iOS 27 and iPadOS 27, watchOS 27. An app may be able to track users across apps and websites without permission.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability described constitutes a significant privacy flaw related to improper state management within the operating system's application framework. This issue allows applications to maintain persistent identifiers or session states that persist beyond their intended lifecycle, enabling them to correlate user activity across different applications and external websites. Such behavior effectively bypasses standard permission models designed to restrict cross-app tracking, thereby undermining user consent mechanisms established by privacy regulations like GDPR and CCPA. The core technical flaw lies in the failure of the system to properly isolate or reset state variables when an application transitions between foreground and background states, or upon termination, allowing residual data to be accessed by subsequent app launches without explicit authorization from the device owner.
From a threat modeling perspective, this vulnerability aligns with CWE-200, which covers Exposure of Sensitive Information to an Unauthorized Actor, specifically in the context of identifier leakage and tracking capabilities. It also maps closely to MITRE ATT&CK technique T1539, Steal Web Session Cookie, as it involves the unauthorized retention or reuse of session-based data that can be leveraged for long-term user profiling. The operational impact is severe from a privacy standpoint, as it enables advertisers and data brokers to build comprehensive profiles of individual users without their knowledge or consent. This erodes trust in the platform's ability to protect personal information and may lead to regulatory penalties for developers who rely on such implicit tracking mechanisms rather than implementing proper opt-in frameworks like Apple’s App Tracking Transparency framework.
The resolution implemented in iOS 26.7, iPadOS 26.7, iOS 27, iPadOS 27, and watchOS 27 addresses this by enforcing stricter state isolation protocols. The updated system ensures that application-specific identifiers are properly invalidated or randomized when an app is suspended or terminated, preventing the accumulation of persistent tracking tokens across sessions. Developers must also adhere to best practices for privacy-preserving design, such as requesting explicit permission before accessing sensitive attributes and minimizing data retention periods. For users, keeping their devices updated with these latest versions ensures that this specific vector for unauthorized cross-app tracking is mitigated. Organizations should audit their applications to ensure they do not rely on implicit state persistence for analytics or advertising purposes, instead adopting privacy-by-design principles that respect user choice and limit data collection to what is strictly necessary for functionality.