CVE-2026-43667 in iOS
Summary
by MITRE • 08/17/2026
A reachable assertion was addressed with improved input validation. This issue is fixed in iOS 18.7.10 and iPadOS 18.7.10. An attacker in a privileged network position may be able to cause a denial-of-service.
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Analysis
by VulDB Data Team • 08/17/2026
The vulnerability described involves a reachable assertion failure within the operating system, specifically affecting iOS and iPadOS versions prior to 18.7.10. In software engineering, an assertion is typically used during development to verify that certain conditions are met; however, when these assertions remain enabled in production builds or fail due to unexpected input states, they can lead to abrupt program termination. This specific flaw allows a remote attacker who holds a privileged position on the network to trigger this condition through crafted network traffic. The core technical issue lies in insufficient validation of incoming data packets before they are processed by critical system components. When malformed or specifically engineered inputs reach these internal handlers, the application logic encounters an unexpected state that violates its preconditions, causing the assertion to fail and resulting in a crash.
From a security architecture perspective, this flaw represents a classic denial-of-service vector where availability is compromised without requiring authentication or code execution privileges on the target device. The attacker does not need to exploit complex memory corruption bugs such as buffer overflows or use-after-free errors; instead, they leverage logic flaws that cause the system to halt its operations entirely. This type of vulnerability aligns with Common Weakness Enumeration category CWE-20, which covers Improper Input Validation, and more specifically relates to scenarios where input validation is bypassed in network-facing services. The impact is immediate and severe for the affected device, as a crash typically requires a reboot or service restart to restore functionality, leading to significant downtime for users relying on their mobile devices for communication and productivity.
The operational impact of this vulnerability extends beyond simple inconvenience. For enterprise environments utilizing Mobile Device Management solutions, repeated denial-of-service attacks could disrupt workforce connectivity and compromise the reliability of critical business applications running on iOS and iPadOS platforms. Since the attack requires a privileged network position, it suggests that an attacker would need to be within range of the local Wi-Fi network or have compromised a router or switch in the same broadcast domain. This limits the scope primarily to physical proximity attacks or insider threats rather than wide-scale internet-based exploitation. However, given the ubiquity of mobile devices and their integration into corporate networks, even localized denial-of-service events can cause substantial operational friction and security incidents that require incident response procedures to resolve.
Mitigation strategies for this vulnerability focus on both immediate patching and long-term architectural improvements. The primary remediation is to update iOS and iPadOS to version 18.7.10 or later, where Apple has implemented improved input validation mechanisms to prevent the assertion from being triggered by malicious payloads. Network administrators should enforce strict access controls on local networks to limit exposure to untrusted devices that could attempt such attacks. Additionally, implementing network monitoring tools capable of detecting anomalous traffic patterns associated with denial-of-service attempts can provide early warning indicators. From a development lifecycle perspective, this incident highlights the importance of rigorous fuzzing and static analysis during software testing phases to identify unreachable code paths or improper error handling before deployment. Adhering to secure coding standards such as those outlined in OWASP guidelines for input validation helps ensure that similar logic flaws are identified and resolved proactively.
In terms of threat intelligence frameworks, this vulnerability can be mapped to the MITRE ATT&CK technique T1499, Endpoint Denial of Service, specifically under methods involving application exhaustion or resource consumption through logical errors. While it does not involve direct exploitation of memory safety vulnerabilities like CWE-120 or CWE-787, it underscores the risk posed by logic-based flaws that bypass standard security controls due to inadequate state management. Security teams should prioritize patching endpoints running affected versions and review network segmentation policies to ensure that privileged network access is restricted to authorized personnel and devices only. Continuous monitoring for signs of device instability or unexpected reboots can also help in identifying potential exploitation attempts in real-time, allowing for rapid containment before widespread disruption occurs.