CVE-2026-0018 Overview
CVE-2026-0018 is a local denial of service vulnerability affecting Google Android. The flaw resides in multiple functions of AccessibilityManagerService.java and stems from improper input validation [CWE-20]. A local application with low privileges can trigger a persistent denial of service against the accessibility subsystem without user interaction. Exploitation does not grant additional execution privileges, but the impact on availability is high because the condition can persist across sessions. Google addressed the issue in the June 2026 Android Security Bulletin.
Critical Impact
A local low-privileged application can induce a persistent denial of service in the Android accessibility framework, disrupting core device functionality without requiring user interaction.
Affected Products
- Google Android 15.0
- Google Android 16.0
- Google Android 16.0 QPR2 Beta 1, Beta 2, and Beta 3
Discovery Timeline
- 2026-06-01 - Google releases fix in the Android Security Bulletin
- 2026-06-01 - CVE-2026-0018 published to NVD
- 2026-06-02 - Last updated in NVD database
Technical Details for CVE-2026-0018
Vulnerability Analysis
The vulnerability exists in AccessibilityManagerService.java, the system service that manages accessibility events, registered accessibility services, and client bindings on Android. Multiple functions in this service fail to properly validate input received from callers. A local attacker with a low-privileged app context can submit malformed or malicious parameters that the service accepts without sufficient sanitization. The resulting state corruption disrupts service operation and remains persistent, meaning normal device usage cannot recover the accessibility framework without remediation. Because accessibility services interact with input, UI, and assistive features, downstream functionality dependent on the service is also impaired.
Root Cause
The root cause is improper input validation [CWE-20] in multiple methods of AccessibilityManagerService.java. The service does not enforce sufficient checks on caller-supplied data before applying state changes, allowing invalid input to corrupt persistent service state.
Attack Vector
The attack requires local access through a low-privileged application installed on the device. No user interaction is required. The malicious app interacts with the accessibility service through standard Android inter-process communication channels and supplies crafted input to the vulnerable functions. The result is a persistent denial of service of the accessibility framework on the affected device.
No public proof-of-concept exploit is available. Technical details are described in the Android Security Bulletin June 2026.
Detection Methods for CVE-2026-0018
Indicators of Compromise
- Repeated crashes, restarts, or unresponsiveness of the Android system_server process tied to accessibility components.
- logcat entries showing exceptions originating from AccessibilityManagerService after third-party app activity.
- Accessibility services becoming unavailable or failing to enumerate following installation or execution of an untrusted application.
Detection Strategies
- Monitor Android device logs for recurring AccessibilityManagerService errors and abnormal binder transactions targeting the accessibility service.
- Track applications that request unusual interactions with accessibility APIs without a legitimate functional need.
- Correlate device-side crash reports with recently installed applications to identify candidate triggers.
Monitoring Recommendations
- Aggregate Android crash and ANR (Application Not Responding) telemetry from managed devices into a central log platform.
- Apply mobile threat defense policies that flag side-loaded apps and apps abusing accessibility-related APIs.
- Alert when devices report patch levels older than the June 2026 Android security patch level.
How to Mitigate CVE-2026-0018
Immediate Actions Required
- Apply the June 2026 Android security patch to all managed devices running Android 15.0 and Android 16.0.
- Enforce a minimum security patch level policy through MDM (Mobile Device Management) to block non-compliant devices from sensitive resources.
- Restrict installation of applications from untrusted sources on enterprise-managed devices.
Patch Information
Google published the fix in the Android Security Bulletin June 2026. Devices must report a security patch level of 2026-06-01 or later to be considered remediated. OEM rollouts may follow Google's release on different schedules, so verify per-device patch availability with the device manufacturer.
Workarounds
- Limit user ability to install third-party applications until the June 2026 patch is deployed.
- Review and remove any non-essential applications that request accessibility-related permissions.
- Reboot affected devices to temporarily restore accessibility service availability if a denial of service condition is triggered.
No configuration-based mitigation replaces the official Google patch. Administrators should prioritize OS update deployment through their existing MDM workflow.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
