CVE-2026-86961 in iOS
Summary
by MITRE • 10/20/2026
A race condition was addressed with additional validation. This issue is fixed in iOS 27 and iPadOS 27, macOS Golden Gate 27. A malicious app may be able to break out of its sandbox.
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Analysis
by VulDB Data Team • 10/20/2026
The disclosed vulnerability represents a critical security flaw rooted in a race condition within the operating system's privilege management or access control mechanisms. Race conditions occur when software performs an operation based on a sequence of events that is not guaranteed, typically involving a time-of-check to time-of-use (TOCTOU) scenario where the state of a resource changes between the initial validation and its actual use. In this specific instance, the underlying issue allowed for a bypass of the sandboxing architecture that isolates applications from one another and from core system resources. The fix implemented in iOS 27, iPadOS 27, and macOS Golden Gate 27 introduces additional validation steps to ensure that access controls are enforced atomically or with sufficient synchronization to prevent an attacker from exploiting the window of vulnerability between permission checks and execution.
From a technical perspective, this flaw aligns closely with CWE-362, which defines concurrent execution race conditions leading to unintended state changes. The malicious application likely exploited a timing gap where it could manipulate system variables or file states after they had been validated by the security subsystem but before those validations were fully committed or locked. This type of vulnerability is particularly dangerous because it does not require complex exploitation techniques such as buffer overflows or injection attacks; instead, it relies on precise timing and concurrent execution to trick the operating system into granting elevated privileges that should have been denied. The presence of additional validation in the patched versions suggests that previous checks were either insufficiently granular or lacked proper locking mechanisms to prevent state manipulation during high-concurrency operations.
The operational impact of this vulnerability is severe, as it effectively nullifies one of the primary defenses against mobile and desktop malware: application sandboxing. By breaking out of its sandbox, a malicious app gains access to sensitive data belonging to other applications, system configurations, and potentially kernel-level resources that are normally inaccessible. This can lead to unauthorized data exfiltration, persistence mechanisms being established within privileged contexts, or the ability to intercept communications intended for legitimate apps. For enterprise environments relying on mobile device management (MDM) solutions, this could result in a complete compromise of endpoint security policies if an attacker leverages these elevated privileges to disable monitoring agents or modify configuration profiles.
This vulnerability is also relevant to MITRE ATT&CK framework techniques related to privilege escalation and defense evasion. Specifically, it maps to T1068 Exploitation for Privilege Escalation, where attackers leverage software vulnerabilities to gain higher-level permissions on a compromised system. Furthermore, breaking the sandbox can be seen as part of T1548 Abuse Elevation Control Mechanism, as the attacker bypasses built-in security controls designed to limit application behavior. The ability to escape confinement allows subsequent stages of an attack chain that would otherwise be blocked by standard isolation protocols, significantly increasing the blast radius of a single compromised application.
Mitigation strategies primarily involve ensuring that all devices are updated to iOS 27, iPadOS 27, or macOS Golden Gate 27 as soon as possible. For organizations managing fleets of Apple devices through MDM solutions, it is critical to prioritize these updates and verify deployment status across all endpoints. In the interim, before patches can be applied, administrators should enforce strict app distribution policies that limit installation to trusted sources only. Additionally, enabling features such as App Privacy Reports and restricting background data access for untrusted applications can help reduce the attack surface by limiting what a potentially malicious application can observe or interact with while still confined within its sandbox boundaries. Regular security audits and monitoring for anomalous privilege escalation attempts should also be implemented to detect any exploitation of this flaw in environments where patching may be delayed due to operational constraints.