CVE-2026-21084 Overview
CVE-2026-21084 is an improper access control vulnerability [CWE-284] affecting Samsung SmartThings versions prior to 1.8.47.24. The flaw allows local attackers to access sensitive information stored or processed by the application. Samsung disclosed the issue as part of its August 2026 Mobile Security Update cycle.
Exploitation requires local access and low privileges on the target device, with no user interaction. The vulnerability primarily impacts confidentiality, with limited integrity and availability effects. Samsung has released an updated version of SmartThings that resolves the issue.
Critical Impact
Local attackers with low privileges can bypass access controls in the SmartThings mobile application to read sensitive data belonging to other users or components on the device.
Affected Products
- Samsung SmartThings mobile application prior to version 1.8.47.24
- Android devices running vulnerable SmartThings builds
- Deployments integrating SmartThings with connected IoT devices
Discovery Timeline
- 2026-08-10 - CVE-2026-21084 published to NVD
- 2026-08-10 - Last updated in NVD database
- August 2026 - Samsung publishes advisory in the Samsung Mobile Security Update
Technical Details for CVE-2026-21084
Vulnerability Analysis
The vulnerability stems from improper access control within the SmartThings Android application. A component of the app exposes sensitive data without adequately verifying whether the calling process or user is authorized to receive it. A local attacker with an unprivileged app or shell access on the same device can query the vulnerable component and retrieve information intended to remain protected.
According to Samsung's advisory, the affected data is characterized as sensitive information. In mobile ecosystems, this class of flaw typically arises from exported Android components (activities, services, content providers, or broadcast receivers) that omit permission checks or rely on signature protection levels incorrectly. It may also involve files or shared preferences stored with permissive filesystem modes.
Root Cause
The root cause is an access control gap [CWE-284] in a SmartThings interface reachable from other processes on the device. The affected component does not correctly validate the identity or privileges of the caller before returning protected information. Samsung addressed the issue in SmartThings 1.8.47.24 by tightening the authorization checks on the impacted interface.
Attack Vector
The attack vector is local. A malicious application installed on the same Android device, or an attacker with local shell access, can invoke the vulnerable SmartThings component and extract sensitive data without triggering user interaction. Remote exploitation over the network is not indicated by the advisory. The vulnerability does not directly enable code execution or account takeover, but disclosed data may facilitate follow-on attacks against connected IoT devices and cloud accounts.
No public proof-of-concept, exploit database entry, or CISA KEV listing is available for this issue at the time of publication. The current EPSS probability is 0.091%.
Detection Methods for CVE-2026-21084
Indicators of Compromise
- Presence of SmartThings versions earlier than 1.8.47.24 on managed Android devices
- Unexpected third-party applications that request or interact with SmartThings components
- Unusual inter-process communication targeting SmartThings package identifiers in device logs
Detection Strategies
- Inventory installed SmartThings versions across the mobile fleet using mobile device management (MDM) reporting
- Review Android application logs and audit tools for cross-app calls into SmartThings exported components
- Correlate SmartThings account activity with device-level app installation events to identify anomalies
Monitoring Recommendations
- Alert on Android devices reporting SmartThings versions below 1.8.47.24 after the patch deadline
- Monitor for sideloaded or newly installed applications on devices that also run SmartThings
- Track SmartThings cloud audit events for unexpected data reads following local access
How to Mitigate CVE-2026-21084
Immediate Actions Required
- Update SmartThings to version 1.8.47.24 or later through Google Play or Samsung Galaxy Store
- Enforce the updated minimum version through MDM compliance policies on corporate-managed devices
- Restrict installation of untrusted third-party applications on devices running SmartThings
Patch Information
Samsung resolved CVE-2026-21084 in SmartThings 1.8.47.24. Details are published in the Samsung Mobile Security Update for August 2026. Users should install the patched version from official application stores; no manual configuration change is required after the update.
Workarounds
- Remove the SmartThings application from devices that cannot be updated to 1.8.47.24
- Limit device access to trusted users and avoid installing untrusted apps alongside SmartThings
- Review connected IoT device permissions in the SmartThings account and revoke unused integrations
# Verify installed SmartThings version on an Android device via ADB
adb shell dumpsys package com.samsung.android.oneconnect | grep versionName
# Expected output should show versionName=1.8.47.24 or higher
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
